Next Article in Journal
Intra-Articular Collagen Injections for Osteoarthritis: A Narrative Review
Next Article in Special Issue
Solvent Extraction for Separation of Indonesian Oil Sands
Previous Article in Journal
Mental Health Conditions– and Substance Use—Associated Emergency Department Visits during the COVID-19 Pandemic in Nevada, USA
Previous Article in Special Issue
Impact of Different Lignin Sources on Nitrogen−Doped Porous Carbon toward the Electrocatalytic Oxygen Reduction Reaction
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review

1
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
2
Frontier Institute of Chip and System, Fudan University, Shanghai 200438, China
3
Key Laboratory of Optoelectronic Technology and Systems of Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
4
Laundry Appliances Business Division of Midea Group, Wuxi 214028, China
*
Authors to whom correspondence should be addressed.
Int. J. Environ. Res. Public Health 2023, 20(5), 4388; https://doi.org/10.3390/ijerph20054388
Submission received: 6 February 2023 / Revised: 24 February 2023 / Accepted: 27 February 2023 / Published: 1 March 2023

Abstract

:
The emission of harmful gases has seriously exceeded relative standards with the rapid development of modern industry, which has shown various negative impacts on human health and the natural environment. Recently, metal–organic frameworks (MOFs)-based materials have been widely used as chemiresistive gas sensing materials for the sensitive detection and monitoring of harmful gases such as NOx, H2S, and many volatile organic compounds (VOCs). In particular, the derivatives of MOFs, which are usually semiconducting metal oxides and oxide–carbon composites, hold great potential to prompt the surface reactions with analytes and thus output amplified resistance changing signals of the chemiresistors, due to their high specific surface areas, versatile structural tunability, diversified surface architectures, as well as their superior selectivity. In this review, we introduce the recent progress in applying sophisticated MOFs-derived materials for chemiresistive gas sensors, with specific emphasis placed on the synthesis and structural regulation of the MOF derivatives, and the promoted surface reaction mechanisms between MOF derivatives and gas analytes. Furthermore, the practical application of MOF derivatives for chemiresistive sensing of NO2, H2S, and typical VOCs (e.g., acetone and ethanol) has been discussed in detail.

1. Introduction

With the recent rapid development of cities and industry, volatile organic compounds (VOCs) and other harmful gases are being released at an increasing rate, which upon entry into the air destroys the environmental and ecological balance [1,2]. For example, NOx causes photochemical smog, SO2 causes acid rain and haze, and HCHO causes inflammation and cancer, each of which is harmful and has a noticeable impact on human health [3,4,5,6]. Sensors, which are monitoring devices that convert monitored information into electrical signals or other information, have many advantages, such as simple operation, facile pretreatment, low cost and real-time detection compared with traditional gas analysis instruments such as gas chromatographs and mass spectrometers [7,8,9,10,11,12]. In previous studies, electrochemical sensors, optical fiber sensors, and capacitive sensors have been applied for the detection of harmful gases [13,14,15,16,17]. However, these sensors have a series of disadvantages, such as low sensitivity, complex design, and high prices. Chemiresistive gas sensors, as a kind of promising chemical gas sensor, are ohmic contact resistors with two electrodes displaying resistance changes when sensing materials come into contact with the analyte, and the nature of the chemical reaction and the concentration change of the analyte can be inferred by this resistance change [18,19]. Chemiresistive gas sensors avoid the shortcomings of other types of gas sensors commonly used in previous research due to their several advantages, such as having a fast response speed, high sensitivity, easy-to-design structure, simple operation, and low price; thus, they have been widely used in recent years. It is important to choose gas sensors that are suitable for the recording and monitoring of chemical stimuli and variations in the environment in order to study the changeable trends of harmful gases and in turn set more effective pollution control plans, control the emissions of gas pollutants, and reduce their negative effects. The microstructure and surface state of sensitive materials can influence the performance of gas sensors. Extraordinary structures can increase the number of surface active sites and accelerate the reaction rates [20,21,22,23]. For example, a large contact area caused by hollow or porous structures can increase the degree and rate of chemical reactions. Lee et al. studied the acetone sensing properties of ZnO nanoparticles with different oxygen vacancies [24]. The study showed that the existence of oxygen vacancies brought about an excellent response because controlling the surface defects represented a way to change the sensing properties. O2 in the air adsorbs on the surface of ZnO nanoparticles and combines with the electrons above to form O2, wherein the oxygen vacancy can be used as an electron donor [25,26,27,28,29,30]. When the sensor is exposed to acetone, O2 reacts with acetone, and the adsorbed electrons are then released back into the conduction band (CB), resulting in the reduction of the depletion layer thickness and resistance. Thus, it is important to choose a suitable sensitive material.
Metal–organic frameworks (MOFs), a burgeoning class of metal-coordinated cationic polymer nanomaterials consisting of metal cation aggregates which are linked by organic ligand molecules or metal cations, have large specific surface areas, tunable and porous structures, and high structural stability. Furthermore, MOFs also show excellent adsorption capacity and low environmental toxicity, making them promising candidates for environmental applications such as adsorption and catalysis [31,32]. However, MOFs are generally electrical insulators with poor conductivity. This greatly hinders their usage for chemiresistive gas sensing materials due to the foreseeable intrinsic low response values. In this case, pristine MOFs have been combined with other conductive materials to form heterostructures, either doped with heteroatoms, or simply calcined at high temperature to generate metal oxide-carbon composites (i.e., MOF derivatives) to improve their sensing performance [33,34]. For example, a uniform three-dimensional MXene/MOF composite, Ti3C2TX/ZIF-67/CoV2O6, has been obtained by a co-precipitation reaction, which integrated the conductivity of MXene and the redox activity of the MOF [35]. Generally, MOFs are suitable precursor materials which can be used as an ideal template to synthesize porous metal nano-oxides with an ideal structure. In this regard, their derivatives, such as metal oxides, carbon materials, and their composites, are often used as gas sensing materials due to their high chemical stability, rich structural diversity, large specific surface areas with highly porous structures, considerable temperature resistance, low environmental and physiological toxicity, and many other advantages [19,36,37,38,39]. Furthermore, the doping of heteroatoms into MOFs is also a method for improving sensing performance. Doping heteroatoms can reduce the particle size of the sensing material by inducing the formation of oxygen vacancies, increasing the contact area and enhancing the sensing performance [40,41,42,43]. In addition, the ion or compound activation centers formed by doping heteroatoms can be used as catalysts in chemical reactions between detected gases and sensing materials, accelerating reactions and improving the selectivity and response speeds of sensing materials at a low temperature. Thus, doping heteroatoms into metal oxide-based sensing materials is beneficial for improving their gas-sensing properties [33,34,35,36,37,38,39,40,41,42,43,44,45,46,47]. For example, Zhang et al. synthesized Cu–In2O3 hollow nanofibers by doping Cu atoms into In2O3 and used them as H2S-sensing materials. Their study showed that the doping of Cu atoms and the formation of their hollow structure increased the number of active sites, and the small amount of CuO formed by Cu oxidation could combine with In2O3 to synthesize the pn heterojunction, greatly improving selectivity and responsiveness to H2S [48]. In addition, the doped heteroatoms could also accelerate the adsorption and desorption of oxygen to electrons, thus improving response performance [49]. In this paper, we summarize the methods of enhancing the sensing performance of chemiresistive gas sensors for harmful gases, such as by changing the morphology and structure of MOFs, doping heteroatoms, and other design methods.

2. Sensing Principles of Chemiresistive Gas Sensors

The chemiresistive gas sensor, an important part of the gas analysis system, is an instrument which can determine the concentration and composition of detected gas and convert the obtained chemical information into electrical information [50,51]. Chemiresistive gas sensors are often used to detect inorganic small molecular gases and VOCs. Chemiresistive gas sensors react differently when exposed to different inorganic small molecule gases. If exposed to a gas with strong oxidizing or strong reducing properties, the substances in the sensor and the analyte exchange electrons and holes or form a heterojunction to affect the resistance. If exposed to acid and alkaline gas, the substance in the sensor affects the resistance through the occurring chemical adsorption and chemical reaction with the analyte [52]. VOC detection mostly uses polymer as the gas-sensing material of the chemiresistive gas sensor. If exposed to a non-conductive polymer, the sensitive film begins to expand, the conductive path becomes longer, electron transfer becomes more difficult, and the resistance value increases after the polymer absorbs VOCs. However, the resistance value is changed via electron-hole exchange, forming a heterojunction if exposed to conductive polymers [53,54,55,56,57,58]. In previous studies, the performance of chemiresistive sensors has usually been evaluated by the following parameters: (1) Response (R): R = (RairRgas)/Rgas, where Rgas and Rair are the resistance with and without the presence of gaseous analyte; (2) Sensitivity (S): S = δRCt, where Ct is the concentration of the measured gas; (3) Repeatability: Repeatability is measured by comparing the response of the same device to the same concentration of measured gas for multiple cycles; (4) Stability: Stability refers to testing the gas-sensing performance of the same device to the measured gas after being placed at different times, comparing the change in gas sensitivity with time; (5) Selectivity: Selectivity of the gas sensor is evaluated by comparing the response gap of the same device to different gases with the same concentration.

3. Chemiresistive Gas Sensors Using MOF Derivatives

MOF derivatives-based chemiresistive sensors have attracted wide attention. They could simply be synthesized by thermochemical methods such as pyrolysis, using MOF as the template compromising the different functional units including metal ions and carbon species [59].

3.1. NO2 Sensors

NO2, a kind of hazardous vehicle emission product and combustion product of fossil fuels with an acidic nature, can cause many environmental problems, such as acid rain, photochemical smog, haze, and water eutrophication [60,61,62]. Thus, it is very important to develop gas sensors with high sensing performance for NO2 detection. Studies to date have shown that nanostructured metal oxides have higher sensing performance for NO2 [63,64]. Ren et al. used a Zn-based zeolitic imidazolate framework (ZIF-8) as a template to synthesize porous ZnO nanocubes for the detection of NO2 (Figure 1a) [65]. The experiment indicated that as the temperature increased, the organic bonds of the compounds were gradually pyrolyzed, the organic ligands were removed, and the metal nodes were oxidized to metal oxides leaving voids, as demonstrated by scanning electron microscopy (SEM) images of ZIF-8 and ZIF-8 derivatives at different pyrolysis temperatures (Figure 1b,c). By comparing the response of ZIF-8 derivatives synthesized at different pyrolysis temperatures to 1 ppm NO2, it was noted that ZIF-8-500 synthesized at the pyrolysis temperature of 500 °C had the highest response (Figure 1e). Previous studies have confirmed that the charge transfer between absorbed gas and the gas sensor may affect the sensing performance of metal oxide gas sensors. When the gas sensor is exposed to NO2, NO2 adsorbs on the material and takes electrons from the CB of ZnO, causing a resistance increase and producing an electron depletion layer (Figure 1f). Porous ZnO nanocubes inherit the high specific surface area of ZIF-8, and its unique porous hollow polyhedral structure creates numerous gas channels, making it easier for NO2 to adsorb on its surface and take away electrons. Compared with normal ZnO, porous ZnO nanocubes present high sensitivity and a lower NO2 detection limit. In addition, the prepared gas sensor exhibits good selectivity for NO2 compared with other gases (CO, C2H5OH, H2, H2S, NO, NH3). This is attributed to the excellent microstructure and surface states of the nanomaterials.
Materials Institute Lavoisier (MIL)-based materials synthesized from terephthalic acid and metal-centered octahedron (MO4(OH)2, M = In, Ga, Fe), which are organic ligands, have a three-dimensional network structure with ultra-high porosity [66]. Du et al. took MIL (M = In) as a precursor doped with a small amount of Fe ions to synthesize Fe–In2O3 nanorods through thermochemical methods and a pyrolysis process, investigating its NO2 sensing performance (Figure 2a) [44]. By observing the SEM images of In/Fe-MIL-68s with different levels of Fe(III) content, all the samples showed a hexagonal rod-shaped architecture, the Fe-doped In2O3 nanorods had pores on the surface, and the structural size was slightly reduced, which was due to the shrinkage and decomposition of the MOF structure caused by the pyrolysis process. In comparing the high-resolution transmission electron microscopy (HRTEM) images of Fe(0)–In2O3, it was found that doping Fe(III) forms lattice defects because Fe(III) replaces the In3+ ions in the crystal structure (Figure 2d,e). According to Figure 2f,g, Fe(5)–In2O3 nanorods showed excellent responsiveness and selectivity to NO2 compared with similar products because the nanorod exhibits superior NO2 gas-sensing performance at low temperatures due to the high diffusivity, multiple active sites, and wide depletion layer brought by its unique structure. When the sensor is exposed to air, O2 adsorbs on the surface of the nanorods and extracts the electrons in the sensing material, forming O or O2−, which leads to the formation of a potential barrier by bending the energy band and increasing resistance, in turn reflecting the sensing performance of the material for NO2. When the sensor is exposed to NO2 gas, it contacts and combines with the electrons of the sensing material to form NO2, resulting in further band bending, higher potential barrier formation, and the further increase in resistance (Figure 2h). In summary, in order to better adsorb and sense the NO2 molecules, the MOF precursors with high specific surface areas should be selected, and the resulting metal oxide composites are usually doped to improve conductivity, and thereby to improve the electron exchange and sensitivity toward NO2.
With the rapid development of electronic products, wearability and high selectivity have attracted significant attention. In a study by Bag et al., a NO2 sensor based on reduced graphene oxide (rGO)–ZnFe2O4 was developed by uniformly anchor smearing MOF-derived mesoporous ZnFe2O4 microparticles on the rGO sensor layer [67,68]. Because of the synergistic reaction between the mesoporous ZnFe2O4 particles and the rGO sensing layer, the gas sensor showed improved mechanical stretchability and signal stability compared with rGO-only devices, exhibited superior response and sensitivity to NO2, and had good repeatability and selectivity even under high humidity conditions, which is expected to be applied in future wearable electronics.

3.2. Acetone Sensors

Acetone, a harmful VOC, is widely used in the chemical industry and chemical experiments. Trace amounts of acetone gas can cause great harm to the environment and to human health, including headache, coma, and even death. Moreover, acetone is one of the important indicators used for diabetes detection [69,70,71]. Thus, it is very important to develop efficient and sensitive acetone gas sensors. Zhu et al. used Fe-MIL-88B-NH2 as a precursor and MEMS as a substrate to synthesize Fe2O3/C mesoporous nanorods (NR) via simple hydrothermal and pyrolysis reactions, and investigated its acetone-sensing properties [72,73]. The experiment indicated that when the calcination temperature was lower than 500 °C, as the temperature increased, α-Fe2O3 was gradually formed in the compounds, the crystallinity was increased, and the organic molecules were gradually carbonized and decomposed, as shown in the SEM images of the Fe-MOF precursors and their derivatives at different calcination temperatures (Figure 3a,b). Furthermore, the specific surface area of the mesoporous NRs increased significantly after calcination at 300 °C, which was beneficial to their acetone gas-sensing properties. In addition, a hollow structure was formed in the compound, which might have been caused by the lattice rearrangement and the complete decomposition of the organic ligands when the calcination temperature reached 400 °C, as displayed in the TEM images (Figure 3c,d). When the synthesized material was exposed to acetone, the electrons on the Fe2O3 surface were captured by the oxygen adsorbed on it, resulting in an increase in the depletion layer and the potential barrier. The oxygen species adsorbed on its surface reacted with acetone, changing the resistance (Figure 3g). The study showed that the synthesized carbon nanoparticle-modified mesoporous α-Fe2O3 NRs exhibited excellent thermal stability, accurate selectivity, and a fast response to acetone (Figure 3e,f), which may have been due to its large specific surface area and excellent electrical conductivity.
Zhang et al. synthesized a ZnO/Co3O4 nano-heterostructure using ZIF-8/ZIF-67 as a precursor via a facile co-precipitation method [74]. The experiment results demonstrated that ZnO nanopolyhedrons are composed of many small pores. ZnO/Co3O4 nanopolyhedrons exhibit a similar hollow polyhedron structure with ZnO nanopolyhedrons revealed by the SEM and TEM images (Figure 4a,b). The response diagrams of the ZnO and ZnO/Co3O4 thin film sensors to acetone were further observed (Figure 4c,d) in the experiment, which showed that the ZnO/Co3O4 thin film sensor exhibited good selectivity, reproducibility, repeatability, and stability to acetone. When ZnO is exposed to air, oxygen molecules adsorb on the surface of ZnO nanopolyhedrons and obtain electrons to form O2− and O ions, forming a further depletion layer. When ZnO was exposed to acetone, the acetone reacted with the adsorbed oxygen ions, thereby reducing the height and width of the depletion layer and further reducing the resistance of the sensor (Figure 4e). The sensing mechanism of the ZnO/Co3O4 acetone sensor is similar to that of ZnO, while the sensing performance is greatly improved with regard to response, repeatability, and selectivity. This may be facilitated by the superior catalytic performance of Co3O4, the pn heterojunction formed between ZnO and Co3O4, and the unique hollow structure. In general, sophisticated metal oxide-based heterostructures with enhanced porosity and lattice rearrangement, or with a favorable pn heterojunction, could be obtained from designed MOFs as the template, which could consequently achieve a rapid response to acetone as a result, being attributable to the improved carrier dynamics [75,76,77,78].

3.3. Ethanol Sensors

Zhang et al. attempted to synthesize solid, hollow, and hierarchical hollow nanocages with quantum dots (HHQD) of ZnO for ethanol gas sensing [79]. The HHQD-ZnO nanocages were synthesized from the ZIF-8 product with a size of 170 mm (170-ZIF-8) as a precursor, and the SEM images of the 170-ZIF-8 nanocrystals (Figure 5a,b) indicated that the synthesized 170-ZIF-8 precursors had a uniform cage-like morphology with good connectivity between particles. The further study of the TEM images revealed (Figure 5c,d) that the formed HHQD-ZnO nanocages inherited the cage-like morphology of the precursor, presenting a large-area hollow structure and a large specific surface area. According to the response diagram of the HHQD-ZnO nanocages to ethanol gas (Figure 5e), the response value of the HHQD-ZnO nanocage sensor to ethanol was much higher than that of the solid ZnO nanocage sensor, and the sensor showed high selectivity to ethanol gas (Figure 5f), which was due to the unique hollow interpenetrating nanostructure and large specific surface area. When the HHQD-ZnO nanocage sensor was exposed to ethanol, its hollow nanocage structure could adsorb oxygen and carry away free electrons from the CB, thereby increasing the potential barrier and resulting in resistance change.

3.4. H2S Sensors

H2S is a flammable and toxic gas which can be produced in the production processes of food processing plants, paper mills, oil refineries, and other factories, and can also be produced by gas combustion and after the decomposition of human and animal excreta [80,81,82,83,84]. H2S can affect the human nervous system and visual system, causing Alzheimer’s disease, loss of consciousness, and other problems [85]. Thus, it is urgent that H2S detection and monitoring sensing systems are improved in order to reasonably control H2S emissions [86,87]. Li et al. first synthesized CPP-3 (In) microrods and then used Cu2+-impregnated CPP-3 (In) microrods impregnated with Cu2+ as MOF precursors to synthesize bamboo-like CuO/In2O3 heterostructures via heating, cooling, centrifugation, drying, and calcination (Figure 6a) [88]. SEM (Figure 6b) and TEM images (Figure 6c) of CuO/In2O3 showed that the synthesized CuO/In2O3 inherited the rod-like shape of the CPP-3(In) precursor, but the average size was slightly reduced, showing a bamboo-like hollow structure. In addition, the images also showed the existence of pn heterojunctions formed between CuO and In2O3 nanoparticles. By comparing the response values of CuO/In2O3 to different gases (Figure 6d,e), CuO/In2O3 showed excellent selectivity and responsiveness to H2S at low temperatures. Intrinsically, CuO is a p-type compound and In2O3 is an n-type compound. When CuO came into contact with In2O3, holes in the CuO and electrons in the In2O3 flowed in opposite directions, forming an internal electric field, an energy band bending in the depletion layer, and subsequently forming a pn heterojunction, enhancing gas-sensing performance (Figure 6f,g). Finally, the unique mesoporous bamboo-like hollow structure and the facilitated electron transfer resulted from the pn heterojunction, and together enabled the CuO/In2O3 sensor superior selectivity, reproducibility, and sensitivity to H2S. Furthermore, Karuppasamy et al. synthesized Ni4Mo/MoO2@C composite nanospheres via a co-precipitation and high-temperature calcination process using MOF as a precursor [89]. The gas response of the Ni4Mo/MoO2@C composite nanospheres to H2S was 3.5 times and 2.6 times higher than those of Ni-MOF and Mo-MOF, respectively, which was attributed to the synergistic effect of the Ni4Mo/MoO2@C composite nanospheres and the high surface area derived from the unique morphology. Overall, the pn heterojunction with well-defined energy level bending can be introduced into the depletion layer with the reverse flow of holes and electrons, which could afford a reliable detection of H2S at a lower power consumption [90,91,92].

3.5. Other Gas Sensors

Zhang et al. synthesized NiFe2O4 nano-octahedrons via the direct pyrolysis of NiFe-bimetallic MOFs to explore its gas sensing performance to toluene [93]. The study showed that the sensor exhibited a low recovery time, strong stability, high repeatability, and low detection, which was due to the catalytic properties and high specific surface area resulting from its porous structure. Qin et al. synthesized Co3O4 dodecahedrons by calcining a Co-MOF template. The sensing material exhibited good selectivity and high responsiveness to CO because of the large number of Co3+ active sites and surface adsorption of oxygen [94].

4. Conclusions and Future Perspectives

The chemiresistors, a type of chemical gas sensor, can detect the concentration changes of target gases through changes in resistance signals. Studies have shown that the performance of chemiresistors could be promoted by selecting suitable gas-sensing materials to achieve high responsiveness and selectivity to the specific target gas. MOF derivatives synthesized with MOFs as precursors hold great potential in gas sensing due to their unique structures, high selectivity, sensitivity, and versatility. In this review, we summarized the applications of MOF derivatives for sensing NO2, acetone, ethanol, H2S, and several other toxic gases, with their detailed sensing performance and mechanisms being described and discussed.
However, although the novel MOF derivatives-based chemiresistors suggest many new opportunities in in situ detection and monitoring of the harmful gases in industries and in daily life, there are still several challenging points which need to be dealt with:
(1).
The MOF derivatives should successfully maintain or inherit the original high porosity and redox activity of pristine MOFs during the high-temperature pyrolysis process so that they can achieve excellent sensitivity and response as a chemiresistive gas sensor;
(2).
The sophisticated morphologies and precisely tailored physicochemical properties of the MOF derivatives need to be constructed and established by thermochemical or other methods, avoiding from the unfavorable Ostwald ripening process, in order to increase the active surface areas affording adsorption and catalysis reaction with gaseous molecules, and also the surface electron affinity to enhance their resistance changing signals;
(3).
Efficient charge transfer needs to be realized by the construction of a pn junction and other heterojunction interfaces so that rapid response and recovery times are available for the chemiresistive gas sensors;
(4).
The reproducibility and cost control for the preparation of MOF derivatives and the as-resulted chemiresistive sensing devices are still far from satisfactory;
(5).
The realization of self-powered, minimized and potable gas sensing devices based on MOF derivatives is another indispensable future research direction, especially with the rapid development of 5G wireless networks currently taking place;
(6).
Finally, the rapid and efficient data transmission and establishment of the gas sensors-based IoT system, which are of great significance to safer and cleaner production by avoiding the leakage of toxic, harmful, flammable and explosive gases like methane leakage during the exploitation of oil and natural gas, also require the further utilization and optimization of the MOF derivatives-based chemiresistive gas sensors.

Author Contributions

Conceptualization, Y.C. and Q.C.; investigation, H.W.; writing—original draft preparation, H.W. and B.S.; writing—review and editing, Q.C.; supervision, H.Z., K.Y., H.X. and Q.C.; funding acquisition, Q.C. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Natural Science Foundation of China (grant number: 52101213) and the Science and Technology Department of Jiangsu Province of China (grant number: BK20210261, BE2022426). The APC was funded by Southeast University of China.

Data Availability Statement

Not applicable.

Acknowledgments

Qi Cao thanks the “Zhi-Shan” Scholars Programme of the Southeast University of China for its support.

Conflicts of Interest

The authors declare that they have no conflict of interest.

References

  1. Mor, S.; Kumar, S.; Singh, T.; Dogra, S.; Pandey, V.; Ravindra, K. Impact of COVID-19 lockdown on air quality in Chandigarh, India: Understanding the emission sources during controlled anthropogenic activities. Chemosphere 2021, 263, 127978. [Google Scholar] [CrossRef] [PubMed]
  2. Guo, Y.; Wen, M.; Li, G.; An, T. Recent advances in VOC elimination by catalytic oxidation technology onto various nanoparticles catalysts: A critical review. Appl. Catal. B Environ. 2021, 281, 119447. [Google Scholar] [CrossRef]
  3. Zhang, L.; Liang, J.; Wang, Y.; Mou, T.; Lin, Y.; Yue, L.; Li, T.; Liu, Q.; Luo, Y.; Li, N.; et al. High-performance electrochemical NO reduction into NH3 by MoS2 nanosheet. Angew. Chem. Int. Ed. 2021, 133, 25467–25472. [Google Scholar] [CrossRef]
  4. Xu, C.; Zhao, W.; Zhang, M.; Cheng, B. Pollution haven or halo? The role of the energy transition in the impact of FDI on SO2 emissions. Sci. Total Environ. 2021, 763, 143002. [Google Scholar] [CrossRef] [PubMed]
  5. Hu, W.; Wan, L.; Jian, Y.; Ren, C.; Jin, K.; Su, X.; Bai, X.; Haick, H.; Yao, M.; Wu, W. Electronic noses: From advanced materials to sensors aided with data processing. Adv. Mater. Technol. 2019, 4, 1800488. [Google Scholar] [CrossRef] [Green Version]
  6. Cao, Q.; Che, R.; Chen, N. Facile and rapid growth of Ag2S microrod arrays as efficient substrates for both SERS detection and photocatalytic degradation of organic dyes. Chem. Commun. 2014, 50, 4931–4933. [Google Scholar] [CrossRef]
  7. Zhang, D.; Fang, Z.; Wang, L.; Yu, H.; Lu, X.; Song, K.; Teng, J.; Yang, W. Controllable growth of single-crystalline zinc oxide nanosheets under ambient condition toward ammonia sensing with ultrahigh selectivity and sensitivity. J. Adv. Ceram. 2022, 11, 1187–1195. [Google Scholar] [CrossRef]
  8. Cao, Q.; Liu, X.; Yuan, K.; Yu, J.; Liu, Q.; Delaunay, J.J.; Che, R. Gold nanoparticles decorated Ag(Cl, Br) micro-necklaces for efficient and stable SERS detection and visible-light photocatalytic degradation of Sudan I. Appl. Catal. B Environ. 2017, 201, 607–616. [Google Scholar] [CrossRef]
  9. Cheng, Y.F.; Cao, Q.; Zhang, J.; Wu, T.; Che, R. Efficient photodegradation of dye pollutants using a novel plasmonic AgCl microrods array and photo-optimized surface-enhanced Raman scattering. Appl. Catal. B Environ. 2017, 217, 37–47. [Google Scholar] [CrossRef]
  10. Cao, Q.; Yuan, K.; Yu, J.; Delaunay, J.J.; Che, R. Ultrafast self-assembly of silver nanostructures on carbon-coated copper grids for surface-enhanced Raman scattering detection of trace melamine. J. Colloid Interface Sci. 2017, 490, 23–28. [Google Scholar] [CrossRef]
  11. Li, L.; Zou, J.; Han, Y.; Liao, Z.; Lu, P.; Nezamzadeh-Ejhieh, A.; Liu, J.; Peng, Y. Recent advances in Al(III)/In(III)-based MOFs for the detection of pollutants. New J. Chem. 2022, 46, 19577–19592. [Google Scholar] [CrossRef]
  12. Zhou, S.; Lu, L.; Liu, D.; Wang, J.; Sakiyama, H.; Muddassir, M.; Nezamzadeh-Ejhieh, A.; Liu, J. Series of highly stable Cd(II)-based MOFs as sensitive and selective sensors for detection of nitrofuran antibiotic. CrystEngComm 2021, 23, 8043–8052. [Google Scholar] [CrossRef]
  13. Kimmel, D.W.; LeBlanc, G.; Meschievitz, M.E.; Cliffel, D.E. Electrochemical sensors and biosensors. Anal. Chem. 2012, 84, 685–707. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  14. Kim, K.J.; Lu, P.; Culp, J.T.; Ohodnicki, P.R. Metal-organic framework thin film coated optical fiber sensors: A novel waveguide based chemical sensing platform. ACS Sens. 2018, 3, 386–394. [Google Scholar] [CrossRef]
  15. Surya, S.G.; Bhanoth, S.; Majhi, S.M.; More, Y.D.; Teja, V.M.; Chappanda, K.N. A silver nanoparticle-anchored UiO-66 (Zr) metal-organic framework (MOF)-based capacitive gas sensor. CrystEngComm 2019, 21, 7303–7312. [Google Scholar] [CrossRef] [Green Version]
  16. Cao, Q.; Yuan, K.; Liu, Q.; Liang, C.; Wang, X.; Cheng, Y.F.; Li, Q.; Wang, M.; Che, R. Porous Au–Ag alloy particles inlaid AgCl membranes as versatile plasmonic catalytic interfaces with simultaneous, in situ SERS monitoring. ACS Appl. Mater. Interfaces 2015, 7, 18491–18500. [Google Scholar] [CrossRef]
  17. Cao, Q.; Che, R. Tailoring Au–Ag–S composite microstructures in one-pot for both SERS detection and photocatalytic degradation of plasticizers DEHA and DEHP. ACS Appl. Mater. Interfaces 2014, 6, 7020–7027. [Google Scholar] [CrossRef]
  18. Yao, M.S.; Li, W.H.; Xu, G. Metal–organic frameworks and their derivatives for electrically-transduced gas sensors. Coord. Chem. Rev. 2021, 426, 213479. [Google Scholar] [CrossRef]
  19. Wang, X.F.; Song, X.Z.; Sun, K.M.; Cheng, L.; Ma, W. MOFs-derived porous nanomaterials for gas sensing. Polyhedron 2018, 152, 155–163. [Google Scholar] [CrossRef]
  20. Cao, Q.; Zhang, J.; Zhang, H.; Xu, J.; Che, R. Dual-surfactant templated hydrothermal synthesis of CoSe2 hierarchical microclews for dielectric microwave absorption. J. Adv. Ceram. 2022, 11, 504–514. [Google Scholar] [CrossRef]
  21. Cao, Q.; Hao, S.; Wu, Y.; Pei, K.; You, W.; Che, R. Interfacial charge redistribution in interconnected network of Ni2P–Co2P boosting electrocatalytic hydrogen evolution in both acidic and alkaline conditions. Chem. Eng. J. 2021, 424, 130444. [Google Scholar] [CrossRef]
  22. Cao, Q.; Yu, J.; Yuan, K.; Zhong, M.; Delaunay, J.J. Facile and large-area preparation of porous Ag3PO4 photoanodes for enhanced photoelectrochemical water oxidation. ACS Appl. Mater. Interfaces 2017, 9, 19507–19512. [Google Scholar] [CrossRef] [PubMed]
  23. Bian, Y.; Zhang, C.; Wang, H.; Cao, Q. Degradable nanofiber for eco-friendly air filtration: Progress and perspectives. Sep. Purif. Technol. 2023, 306, 122642. [Google Scholar] [CrossRef]
  24. Lee, J.; Choi, Y.; Park, B.J.; Han, J.W.; Lee, H.S.; Park, J.H.; Lee, W. Precise control of surface oxygen vacancies in ZnO nanoparticles for extremely high acetone sensing response. J. Adv. Ceram. 2022, 11, 769–783. [Google Scholar] [CrossRef]
  25. Xu, J.; Zhang, C. Oxygen vacancy engineering on cerium oxide nanowires for room-temperature linalool detection in rice aging. J. Adv. Ceram. 2022, 11, 1559–1570. [Google Scholar] [CrossRef]
  26. Hao, S.; Liu, J.; Cao, Q.; Zhao, Y.; Zhao, X.; Pei, K.; Zhang, J.; Chen, G.; Che, R. In-situ electrochemical pretreatment of hierarchical Ni3S2-based electrocatalyst towards promoted hydrogen evolution reaction with low overpotential. J. Colloid Interface Sci. 2020, 559, 282–290. [Google Scholar] [CrossRef]
  27. Yu, J.; Cao, Q.; Li, Y.; Long, X.; Yang, S.; Clark, J.K.; Nakabayashi, M.; Shibata, N.; Delaunay, J.J. Defect-rich NiCeOx electrocatalyst with ultrahigh stability and low overpotential for water oxidation. ACS Catal. 2019, 9, 1605–1611. [Google Scholar] [CrossRef]
  28. Yu, J.; Wang, J.; Long, X.; Chen, L.; Cao, Q.; Wang, J.; Qiu, C.; Lim, J.; Yang, S. Formation of FeOOH nanosheets induces substitutional doping of CeO2−x with high-valence Ni for efficient water oxidation. Adv. Energy Mater. 2021, 11, 2002731. [Google Scholar] [CrossRef]
  29. Yuan, K.; Cao, Q.; Lu, H.L.; Zhong, M.; Zheng, X.; Chen, H.Y.; Wang, T.; Delaunay, J.J.; Luo, W.; Zhang, L.; et al. Oxygen-deficient WO3−x@TiO2−x core-shell nanosheets for efficient photoelectrochemical oxidation of neutral water solutions. J. Mater. Chem. A 2017, 5, 14697–14706. [Google Scholar] [CrossRef]
  30. Zeng, X.; Zhao, Y.; Hu, X.; Stucky, G.D.; Moskovits, M. Rational component and structure design of noble-metal composites for optical and catalytic applications. Small Struct. 2021, 2, 2000138. [Google Scholar] [CrossRef]
  31. Wu, Y.; Pang, H.; Liu, Y.; Wang, X.; Yu, S.; Fu, D.; Chen, J.; Wang, X. Environmental remediation of heavy metal ions by novel-nanomaterials: A review. Environ. Pollut. 2019, 246, 608–620. [Google Scholar] [CrossRef] [PubMed]
  32. Tchinsa, A.; Hossain, M.F.; Wang, T.; Zhou, Y. Removal of organic pollutants from aqueous solution using metal organic frameworks (MOFs)-based adsorbents: A review. Chemosphere 2021, 284, 131393. [Google Scholar] [PubMed]
  33. Koo, W.T.; Jang, J.S.; Kim, I.D. Metal-organic frameworks for chemiresistive sensors. Chem 2019, 5, 1938–1963. [Google Scholar] [CrossRef]
  34. Zeng, X.; Nie, T.; Zhao, C.; Zhu, G.; Zhang, X.; Yu, R.; Stucky, G.D.; Che, R. Coupling between the 2D “ligand” and 2D “host” and their assembled hierarchical heterostructures for electromagnetic wave absorption. ACS Appl. Mater. Interfaces 2022, 14, 41235–41245. [Google Scholar] [CrossRef]
  35. Liu, C.; Bai, Y.; Li, W.; Yang, F.; Zhang, G.; Pang, H. In situ growth of three-dimensional MXene/metal–organic framework composites for high performance supercapacitors. Angew. Chem. Int. Ed. 2022, 61, e2021162822022. [Google Scholar]
  36. Qin, L.; Liang, F.; Li, Y.; Wu, J.; Guan, S.; Wu, M.; Xie, S.; Luo, M.; Ma, D. A 2D porous zinc-organic framework platform for loading of 5-fluorouracil. Inorganics 2022, 10, 202. [Google Scholar] [CrossRef]
  37. Qin, L.; Li, Y.; Liang, F.; Li, L.; Lan, Y.; Li, Z.; Lu, X.; Yang, M.; Ma, D. A microporous 2D cobalt-based MOF with pyridyl sites and open metal sites for selective adsorption of CO2. Microporous Mesoporous Mater. 2022, 341, 112098. [Google Scholar] [CrossRef]
  38. Dong, X.; Li, D.; Li, Y.; Sakiyama, H.; Muddassir, M.; Pan, Y.; Srivastava, D.; Kumar, A. A 3,8-connected Cd(II)-based metal-organic framework as an appropriate luminescent sensor for the antibiotic sulfasalazine. CrystEngComm 2022, 24, 7157–7165. [Google Scholar]
  39. Cao, Q.; Li, Q.; Pi, Z.; Zhang, J.; Sun, L.W.; Xu, J.; Cao, Y.; Cheng, J.; Bian, Y. Metal–organic-framework-derived ball-flower-like porous Co3O4/Fe2O3 heterostructure with enhanced visible-light-driven photocatalytic activity. Nanomaterials 2022, 12, 904. [Google Scholar] [CrossRef]
  40. Lee, C.S.; Li, H.Y.; Kim, B.Y.; Jo, Y.M.; Byun, H.G.; Hwang, I.S.; Abdel-Hady, F.; Wazzan, A.A.; Lee, J.H. Discriminative detection of indoor volatile organic compounds using a sensor array based on pure and Fe-doped In2O3 nanofibers. Sens. Actuators B Chem. 2019, 285, 193–200. [Google Scholar] [CrossRef]
  41. Wei, D.; Jiang, W.; Gao, H.; Chuai, X.; Liu, F.; Liu, F.; Sun, P.; Liang, X.; Gao, Y.; Yan, X.; et al. Facile synthesis of La-doped In2O3 hollow microspheres and enhanced hydrogen sulfide sensing characteristics. Sens. Actuators B Chem. 2018, 276, 413–420. [Google Scholar] [CrossRef]
  42. Shen, J.; Li, F.; Yin, B.; Sun, L.; Chen, C.; Wen, S.; Chen, Y.; Ruan, S. Enhanced ethyl acetate sensing performance of Al-doped In2O3 microcubes. Sens. Actuators B Chem. 2017, 253, 461–469. [Google Scholar] [CrossRef]
  43. Bai, S.; Guo, T.; Zhao, Y.; Sun, J.; Li, D.; Chen, A.; Liu, C.C. Sensing performance and mechanism of Fe-doped ZnO microflowers. Sens. Actuators B Chem. 2014, 195, 657–666. [Google Scholar] [CrossRef]
  44. Du, W.; Si, W.; Zhao, J.; Wang, F.; Han, Z.; Wang, Z.; Liu, W.; Lu, G.; Liu, J.; Wu, L. Mesoporous Fe-doped In2O3 nanorods derived from metal organic frameworks for enhanced nitrogen dioxide detection at low temperature. Ceram. Int. 2020, 46, 20385–20394. [Google Scholar] [CrossRef]
  45. Yu, J.; Cao, Q.; Qiu, C.; Chen, L.; Delaunay, J.J. Modulating Ni/Ce ratio in NiyCe100−yOx electrocatalysts for enhanced water oxidation. Nanomaterials 2021, 11, 437. [Google Scholar] [CrossRef]
  46. Cao, Q.; Yu, J.; Cao, Y.; Delaunay, J.J.; Che, R. Unusual effects of vacuum annealing on large-area Ag3PO4 microcrystalline film photoanode boosting cocatalyst- and scavenger-free water splitting. J. Mater. 2021, 7, 929–939. [Google Scholar] [CrossRef]
  47. Li, Q.; Huang, Z.; Guan, P.; Su, R.; Cao, Q.; Chao, Y.; Shen, W.; Guo, J.; Xu, H.; Che, R. Simultaneous Ni doping at atom scale in ceria and assembling into well-defined lotuslike structure for enhanced catalytic performance. ACS Appl. Mater. Interfaces 2017, 9, 16243–16251. [Google Scholar] [CrossRef] [Green Version]
  48. Zhang, Y.; Han, S.; Wang, M.; Liu, S.; Liu, G.; Meng, X.; Xu, Z.; Wang, M.; Qiao, G. Electrospun Cu-doped In2O3 hollow nanofibers with enhanced H2S gas sensing performance. J. Adv. Ceram. 2022, 11, 427–442. [Google Scholar] [CrossRef]
  49. Zhang, C.; Huan, Y.; Li, Y.; Luo, Y.; Debliquy, M. Low concentration isopropanol gas sensing properties of Ag nanoparticles decorated In2O3 hollow spheres. J. Adv. Ceram. 2022, 11, 379–391. [Google Scholar] [CrossRef]
  50. Zhang, M.; Liu, K.; Zhang, X.; Wang, B.; Xu, X.; Du, X.; Yang, C.; Zhang, K. Interfacial energy barrier tuning of hierarchical Bi2O3/WO3 heterojunctions for advanced triethylamine sensor. J. Adv. Ceram. 2022, 11, 1860–1872. [Google Scholar] [CrossRef]
  51. Yuan, K.; Wang, C.Y.; Zhu, L.Y.; Cao, Q.; Yang, J.H.; Li, X.X.; Huang, W.; Wang, Y.Y.; Lu, H.L.; Zhang, D.W. Fabrication of a micro-electromechanical system-based acetone gas sensor using CeO2 nanodot-decorated WO3 nanowires. ACS Appl. Mater. Interfaces 2020, 12, 14095–14104. [Google Scholar] [CrossRef] [PubMed]
  52. Lonergan, M.; Severin, E.; Doleman, B.; Beaber, S.A.; Grubbs, R.H.; Lewis, N.S. Array-based vapor sensing using chemically sensitive carbon black-polymer resistors. Chem. Mater. 1996, 8, 2298–2312. [Google Scholar] [CrossRef] [Green Version]
  53. Spitalsky, Z.; Tasis, D.; Papagelis, K.; Galiotis, C. Carbon nanotube-polymer composites: Chemistry, processing, mechanical and electrical properties. Prog. Polym. Sci. 2010, 35, 357–401. [Google Scholar] [CrossRef]
  54. Yuan, K.; Zhu, L.Y.; Cao, Q.; Ma, H.P.; Tao, J.J.; Huang, W.; Lu, H.L. ALD-based hydrothermal facile synthesis of a dense WO3@TiO2-Fe2O3 nanodendrite array with enhanced photoelectrochemical properties. J. Mater. Chem C 2020, 8, 6756–6762. [Google Scholar] [CrossRef]
  55. Siahroudi, M.G.; Daryakenari, A.A.; Molamahaleh, Y.B.; Cao, Q.; Daryakenari, M.A.; Delaunay, J.J.; Siavoshi, H.; Molaei, F. Ethylene glycol assisted solvo-hydrothermal synthesis of NGr-Co3O4 nanostructures for ethanol electrooxidation. Int. J. Hydrogen Energy 2020, 45, 30357–30366. [Google Scholar] [CrossRef]
  56. Liu, Q.; Cao, Q.; Bi, H.; Liang, C.; Yuan, K.; She, W.; Yang, Y.; Che, R. CoNi@SiO2@TiO2 and CoNi@air@TiO2 microspheres with strong wideband microwave absorption. Adv. Mater. 2016, 28, 486–490. [Google Scholar] [CrossRef]
  57. Hao, S.; Cao, Q.; Yang, L.; Che, R. Morphology-optimized interconnected Ni3S2 nanosheets coupled with Ni(OH)2 nanoparticles for enhanced hydrogen evolution reaction. J. Alloys Compd. 2020, 827, 154163. [Google Scholar] [CrossRef]
  58. Yuan, K.; Cao, Q.; Li, X.; Chen, H.Y.; Deng, Y.; Wang, Y.Y.; Luo, W.; Lu, H.L.; Zhang, D.W. Synthesis of WO3@ZnWO4@ZnO-ZnO hierarchical nanocactus arrays for efficient photoelectrochemical water splitting. Nano Energy 2017, 41, 543–551. [Google Scholar] [CrossRef]
  59. Yin, Z.; Wan, S.; Yang, J.; Kurmoo, M.; Zeng, M.H. Recent advances in post-synthetic modification of metal-organic frameworks: New types and tandem reactions. Coord. Chem. Rev. 2019, 378, 500–512. [Google Scholar] [CrossRef]
  60. Agrawal, A.V.; Kumar, N.; Kumar, M. Strategy and future prospects to develop room-temperature recoverable NO2 gas sensor based on two-dimensional molybdenum sulfide. Nano-Micro Lett. 2021, 13, 38. [Google Scholar] [CrossRef]
  61. Bauwens, M.; Compernolle, S.; Stavrakou, T.; Müller, J.F.; van Gent, J.; Eskes, H.; Levelt, P.F.; van der A, R.; Veefkind, J.P.; Vlietinck, J.; et al. Impact of coronavirus outbreak on NO2 pollution assessed using TROPOMI and OMI observations. Geophys. Res. Lett. 2020, 47, e2020GL087978. [Google Scholar] [CrossRef] [PubMed]
  62. Muhammad, S.; Long, X.; Salman, M. COVID-19 pandemic and environmental pollution: A blessing in disguise? Sci. Total Environ. 2020, 728, 138820. [Google Scholar] [CrossRef] [PubMed]
  63. Tan, J.; Hussain, S.; Ge, C.; Wang, M.; Shah, S.; Liu, G.; Qiao, G. ZIF-67 MOF-derived unique double-shelled Co3O4/NiCo2O4 nanocages for superior gas-sensing performances. Sens. Actuators B Chem. 2020, 303, 127251. [Google Scholar] [CrossRef]
  64. Drobek, M.; Kim, J.H.; Bechelany, M.; Vallicari, C.; Julbe, A.; Kim, S.S. MOF-based membrane encapsulated ZnO nanowires for enhanced gas sensor selectivity. ACS Appl. Mater. Interfaces 2016, 8, 8323–8328. [Google Scholar] [CrossRef]
  65. Ren, X.; Xu, Z.; Liu, D.; Li, Y.; Zhang, Z.; Tang, Z. Conductometric NO2 gas sensors based on MOF-derived porous ZnO nanoparticles. Sens. Actuators B Chem. 2022, 357, 131384. [Google Scholar] [CrossRef]
  66. Volkringer, C.; Meddouri, M.; Loiseau, T.; Guillou, N.; Marrot, J.; Férey, G.; Haouas, M.; Taulelle, F.; Audebrand, N.; Latroche, M. The Kagomé topology of the gallium and indium metal-organic framework types with a MIL-68 structure: Synthesis, XRD, solid-state NMR characterizations, and hydrogen adsorption. Inorg. Chem. 2008, 47, 11892–11901. [Google Scholar] [CrossRef]
  67. Bag, A.; Kumar, M.; Moon, D.B.; Hanif, A.; Sultan, M.J.; Yoon, D.H.; Lee, N.E. A room-temperature operable and stretchable NO2 gas sensor composed of reduced graphene oxide anchored with MOF-derived ZnFe2O4 hollow octahedron. Sens. Actuators B Chem. 2021, 346, 130463. [Google Scholar] [CrossRef]
  68. Li, C.; Cao, Q.; Wang, F.; Xiao, Y.; Li, Y.; Delaunay, J.J.; Zhu, H. Engineering graphene and TMDs based van der Waals heterostructures for photovoltaic and photoelectrochemical solar energy conversion. Chem. Soc. Rev. 2018, 47, 4981–5037. [Google Scholar] [CrossRef]
  69. Liu, M.; Wang, Z.; Song, P.; Yang, Z.; Wang, Q. Flexible MXene/rGO/CuO hybrid aerogels for high performance acetone sensing at room temperature. Sens. Actuators B Chem. 2021, 340, 129946. [Google Scholar] [CrossRef]
  70. Parmar, B.; Bisht, K.K.; Rachuri, Y.; Suresh, E. Zn(II)/Cd(II) based mixed ligand coordination polymers as fluorosensors for aqueous phase detection of hazardous pollutants. Inorg. Chem. Front. 2020, 7, 1082–1107. [Google Scholar] [CrossRef]
  71. Ma, X.; Zhou, X.; Gong, Y.; Han, N.; Liu, H.; Chen, Y. MOF-derived hierarchical ZnO/ZnFe2O4 hollow cubes for enhanced acetone gas-sensing performance. RSC Adv. 2017, 7, 34609–34617. [Google Scholar] [CrossRef] [Green Version]
  72. Zhu, L.Y.; Yuan, K.; Li, Z.C.; Miao, X.Y.; Wang, J.C.; Sun, S.; Devi, A.; Lu, H.L. Highly sensitive and stable MEMS acetone sensors based on well-designed α-Fe2O3/C mesoporous nanorods. J. Colloid Interface Sci. 2022, 622, 156–168. [Google Scholar] [CrossRef] [PubMed]
  73. Zhu, L.Y.; Miao, X.Y.; Ou, L.X.; Mao, L.W.; Yuan, K.; Sun, S.; Devi, A.; Lu, H.L. Heterostructured α-Fe2O3@ZnO@ZIF-8 core-shell nanowires for a highly selective MEMS-based ppb-level H2S gas sensor system. Small 2022, 18, 2204828. [Google Scholar] [CrossRef]
  74. Zhang, D.; Yang, Z.; Wu, Z.; Dong, G. Metal-organic frameworks-derived hollow zinc oxide/cobalt oxide nanoheterostructure for highly sensitive acetone sensing. Sens. Actuators B Chem. 2019, 283, 42–51. [Google Scholar] [CrossRef]
  75. Bayan, E.M.; Petrov, V.V.; Volkova, M.G.; Storozhenko, V.Y.; Chernyshev, A.V. SnO2–ZnO nanocomposite thin films: The influence of structure, composition and crystallinity on optical and electrophysical properties. J. Adv. Dielectr. 2021, 11, 2160008. [Google Scholar] [CrossRef]
  76. Uddin, M.F.; Ullah, M.S.; Hoque, S.M.; Khan, F.A.; Momin, A.A.; Islam, S.R.; Salehin, F.; Hakim, M.A. Electrical transport properties of V2O5-added Ni–Co–Zn ferrites. J. Adv. Dielectr. 2021, 11, 2150025. [Google Scholar] [CrossRef]
  77. Guerra, J.D.S.; Guarany, C.A.; Lima, E.C.; Araújo, E.B.; Garcia, J.E. Exploring the electromechanical response and electric field-induced dielectric anomalies in PMN–PT electroceramics. J. Adv. Dielectr. 2021, 11, 2140005. [Google Scholar] [CrossRef]
  78. Manan, A.; Rehman, M.U.; Ullah, A.; Ahmad, A.S.; Iqbal, Y.; Qazi, I.; Khan, M.A.; Shah, H.U.; Wazir, A.H. High energy storage density with ultra-high efficiency and fast charging–discharging capability of sodium bismuth niobate lead-free ceramics. J. Adv. Dielectr. 2021, 11, 2150018. [Google Scholar] [CrossRef]
  79. Zhang, X.; Lan, W.; Xu, J.; Luo, Y.; Pan, J.; Liao, C.; Yang, L.; Tan, W.; Huang, X. ZIF-8 derived hierarchical hollow ZnO nanocages with quantum dots for sensitive ethanol gas detection. Sens. Actuators B Chem. 2019, 289, 144–152. [Google Scholar] [CrossRef]
  80. Wang, X.; Li, S.; Xie, L.; Li, X.; Lin, D.; Zhu, Z. Low-temperature and highly sensitivity H2S gas sensor based on ZnO/CuO composite derived from bimetal metal-organic frameworks. Ceram. Int. 2020, 46, 15858–15866. [Google Scholar] [CrossRef]
  81. Pan, W.; Zhang, Y.; Yu, S.; Liu, X.; Zhang, D. Hydrogen sulfide gas sensing properties of metal organic framework derived α-Fe2O3 hollow nanospheres decorated with MoSe2 nanoflowers. Sens. Actuators B Chem. 2021, 344, 130221. [Google Scholar] [CrossRef]
  82. Ngoc, T.M.; Van Duy, N.; Hung, C.M.; Hoa, N.D.; Nguyen, H.; Tonezzer, M.; Hieu, N.V. Self-heated Ag-decorated SnO2 nanowires with low power consumption used as a predictive virtual multisensor for H2S-selective sensing. Anal. Chim. Acta 2019, 1069, 108–116. [Google Scholar] [CrossRef] [PubMed]
  83. Cao, Q.; Che, R.; Chen, N. Scalable synthesis of Cu2S double-superlattice nanoparticle systems with enhanced UV/visible-light-driven photocatalytic activity. Appl. Catal. B Environ. 2015, 162, 187–195. [Google Scholar] [CrossRef]
  84. Cao, Q.; Cheng, Y.F.; Bi, H.; Zhao, X.; Yuan, K.; Liu, Q.; Li, Q.; Wang, M.; Che, R. Crystal defect-mediated band-gap engineering: A new strategy for tuning the optical properties of Ag2Se quantum dots toward enhanced hydrogen evolution performance. J. Mater. Chem. A 2015, 3, 20051–20055. [Google Scholar] [CrossRef]
  85. Cheng, J.; Li, C.; Xiong, Y.; Zhang, H.; Raza, H.; Ullah, S.; Wu, J.; Zhang, G.; Cao, Q.; Zhang, D.; et al. Recent advances in design strategies and multifunctionality of flexible electromagnetic interference shielding materials. Nano-Micro Lett. 2022, 14, 80. [Google Scholar] [CrossRef] [PubMed]
  86. Wan, X.; Wu, L.; Zhang, L.; Song, H.; Lv, Y. Novel metal-organic frameworks-based hydrogen sulfide cataluminescence sensors. Sens. Actuators B Chem. 2015, 220, 614–621. [Google Scholar] [CrossRef]
  87. Huang, C.; Liu, D.; Wang, D.; Guo, H.; Thomas, T.; Attfield, J.P.; Qu, F.; Ruan, S.; Yang, M. Mesoporous Ti0.5Cr0.5N for trace H2S detection with excellent long-term stability. J. Hazard. Mater. 2022, 423, 127193. [Google Scholar] [CrossRef]
  88. Li, S.; Xie, L.; He, M.; Hu, X.; Luo, G.; Chen, C.; Zhu, Z. Metal-organic frameworks-derived bamboo-like CuO/In2O3 heterostructure for high-performance H2S gas sensor with low operating temperature. Sens. Actuators B Chem. 2020, 310, 127828. [Google Scholar] [CrossRef]
  89. Karuppasamy, K.; Sharma, B.; Vikraman, D.; Lee, J.H.; Islam, M.; Santhoshkumar, P.; Kim, H.S. Metal-organic framework-derived Ni4Mo/MoO2@C composite nanospheres as the sensing materials for hydrogen sulfide detection. J. Alloys Compd. 2022, 900, 163421. [Google Scholar] [CrossRef]
  90. Lyapunov, N.; Suen, C.H.; Wong, C.M.; Tang, X.; Ho, Z.L.; Zhou, K.; Chen, X.X.; Liu, H.M.; Zhou, X.; Dai, J.Y. Ultralow switching voltage and power consumption of GeS2 thin film resistive switching memory. J. Adv. Dielectr. 2021, 11, 2150004. [Google Scholar] [CrossRef]
  91. Khatun, N.; Hossain, M.S.; Begum, M.H.A.; Islam, S.; Tanvir, N.I.; Bhuiyan, R.H.; Al-Mamun, M. Effect of sintering temperature on structural, magnetic, dielectric and optical properties of Ni–Mn–Zn ferrites. J. Adv. Dielectr. 2021, 11, 2150028. [Google Scholar] [CrossRef]
  92. Wang, C.L. Photocatalytic degradations of JWS-type kinetics. J. Adv. Dielectr. 2021, 11, 2150029. [Google Scholar] [CrossRef]
  93. Zhang, Y.; Jia, C.; Wang, Q.; Kong, Q.; Chen, G.; Guan, H.; Dong, C. MOFs-derived porous NiFe2O4 nano-octahedrons with hollow interiors for an excellent toluene gas sensor. Nanomaterials 2019, 9, 1059. [Google Scholar] [CrossRef] [Green Version]
  94. Sun, J.; Wang, Y.; Song, P.; Yang, Z.; Wang, Q. Metal-organic framework-derived Cr-doped hollow In2O3 nanoboxes with excellent gas-sensing performance toward ammonia. J. Alloys Compd. 2021, 879, 160472. [Google Scholar] [CrossRef]
Figure 1. (a) Schematics of the synthesis and fabrication process of a ZIF-8 derivatives-based sensor; SEM images of (b) ZIF-8 and (c) ZIF-8 derivatives after 500 °C pyrolysis; (d) TEM images of porous ZIF-8-500; (e) Response value to 1 ppm NO2 at different operating temperatures of ZIF-8-derivatives after different pyrolysis processes; (f) Mechanism for the NO2 sensing process of ZIF-8-500 [65].
Figure 1. (a) Schematics of the synthesis and fabrication process of a ZIF-8 derivatives-based sensor; SEM images of (b) ZIF-8 and (c) ZIF-8 derivatives after 500 °C pyrolysis; (d) TEM images of porous ZIF-8-500; (e) Response value to 1 ppm NO2 at different operating temperatures of ZIF-8-derivatives after different pyrolysis processes; (f) Mechanism for the NO2 sensing process of ZIF-8-500 [65].
Ijerph 20 04388 g001
Figure 2. (a) Synthetic process of the mesoporous Fe-doped In2O3 nanorods derived from In/Fe-MIL-68s; SEM images of (b) In/Fe-MIL-68s precursor with 5 mol.% Fe(III) content and (c) as-resulted Fe(5)–In2O3 nanorods; TEM images of as-resulted (d) Fe(0)–In2O3 and (e) Fe(5)–In2O3 porous nanorods; (f) Response of Fe(0)–In2O3 and Fe(5)–In2O3 porous nanorods toward different concentrations of NO2 at 80 °C; (g) Selectivity of the Fe(5)–In2O3 sensor toward various tested gases with the concentration of 2 ppm at 80 °C; (h) Schematics for the sensing mechanisms of pristine In2O3 and Fe-doped In2O3 nanorods [44].
Figure 2. (a) Synthetic process of the mesoporous Fe-doped In2O3 nanorods derived from In/Fe-MIL-68s; SEM images of (b) In/Fe-MIL-68s precursor with 5 mol.% Fe(III) content and (c) as-resulted Fe(5)–In2O3 nanorods; TEM images of as-resulted (d) Fe(0)–In2O3 and (e) Fe(5)–In2O3 porous nanorods; (f) Response of Fe(0)–In2O3 and Fe(5)–In2O3 porous nanorods toward different concentrations of NO2 at 80 °C; (g) Selectivity of the Fe(5)–In2O3 sensor toward various tested gases with the concentration of 2 ppm at 80 °C; (h) Schematics for the sensing mechanisms of pristine In2O3 and Fe-doped In2O3 nanorods [44].
Ijerph 20 04388 g002
Figure 3. Low- and high-magnification (inset) SEM images of (a) Fe-MOF precursor (Fe-MIL-88B-NH2 NRs) and (b) MOF-derived products obtained under 300 °C; (c) TEM and (d) HRTEM images of as-obtained carbon nanoparticles decorated mesoporous α-Fe2O3 NRs (C-d-mFe2O3-300 NRs); (e) Dynamic response curves of gas sensors based on Fe-MIL-88B-NH2 and C-d-mFe2O3-x (x = 200, 300, 350, 400, and 500) NRs facing different concentrations (0.5–2.5 ppm) of acetone at 225 °C; (f) Responses of C-d-mFe2O3-300 sensor to various gases including NO2, H2S, NH3, C7H8, CH4, HCHO, and CH3COCH3 with the same concentration of 2.5 ppm; (g) Schematic illustration of the acetone sensing process by C-d-mFe2O3-300 NRs [72].
Figure 3. Low- and high-magnification (inset) SEM images of (a) Fe-MOF precursor (Fe-MIL-88B-NH2 NRs) and (b) MOF-derived products obtained under 300 °C; (c) TEM and (d) HRTEM images of as-obtained carbon nanoparticles decorated mesoporous α-Fe2O3 NRs (C-d-mFe2O3-300 NRs); (e) Dynamic response curves of gas sensors based on Fe-MIL-88B-NH2 and C-d-mFe2O3-x (x = 200, 300, 350, 400, and 500) NRs facing different concentrations (0.5–2.5 ppm) of acetone at 225 °C; (f) Responses of C-d-mFe2O3-300 sensor to various gases including NO2, H2S, NH3, C7H8, CH4, HCHO, and CH3COCH3 with the same concentration of 2.5 ppm; (g) Schematic illustration of the acetone sensing process by C-d-mFe2O3-300 NRs [72].
Ijerph 20 04388 g003
Figure 4. SEM (a) and TEM (b) images of the ZIF-8/ZIF-67-derived ZnO/Co3O4 nanopolyhedrons; (c) Selectivity of the ZnO/Co3O4 nanocomposite sensor; (d) Long-term stability over 30 days toward 10, 50, and 100 ppm acetone of the ZnO/Co3O4 nanocomposite sensor; (e) Schematics of the acetone sensing mechanism of the ZnO–Co3O4 heterojunction [74].
Figure 4. SEM (a) and TEM (b) images of the ZIF-8/ZIF-67-derived ZnO/Co3O4 nanopolyhedrons; (c) Selectivity of the ZnO/Co3O4 nanocomposite sensor; (d) Long-term stability over 30 days toward 10, 50, and 100 ppm acetone of the ZnO/Co3O4 nanocomposite sensor; (e) Schematics of the acetone sensing mechanism of the ZnO–Co3O4 heterojunction [74].
Ijerph 20 04388 g004
Figure 5. SEM and TEM images of (a,c) the 170-ZIF-8 precursor and (b,d) the as-derived HHQD-ZnO nanocage; (e) Response of HHQD-ZnO nanocages-based gas sensor toward 100 ppm different target gases (ammonia, formaldehyde, dimethylformamide, acetone, toluene, isopropanol, methanol, propanol, butanol and ethanol, respectively); (f) Responses of the sensors based on HHQD-ZnO, hollow ZnO and solid ZnO to 100 ppm ethanol gas at different operating temperatures [80].
Figure 5. SEM and TEM images of (a,c) the 170-ZIF-8 precursor and (b,d) the as-derived HHQD-ZnO nanocage; (e) Response of HHQD-ZnO nanocages-based gas sensor toward 100 ppm different target gases (ammonia, formaldehyde, dimethylformamide, acetone, toluene, isopropanol, methanol, propanol, butanol and ethanol, respectively); (f) Responses of the sensors based on HHQD-ZnO, hollow ZnO and solid ZnO to 100 ppm ethanol gas at different operating temperatures [80].
Ijerph 20 04388 g005
Figure 6. (a) Schematic illustration of the formation of CuO/In2O3; (b) SEM image of as-prepared samples of CuO/In2O3 (CuO concentration = 3.5 wt%) and corresponding (c) TEM image; (d) Response of each sensor to 5 ppm H2S at different operating temperatures; (e) Selectivity of each sensor to 5 ppm H2S gas and other gases (5, 10, or 50 ppm) at 70 °C; (f) Schematics of carrier transportation and gas-sensing mechanism of the CuO/In2O3 heterostructure; (g) Energy level diagram of CuO/In2O3 heterostructure [88].
Figure 6. (a) Schematic illustration of the formation of CuO/In2O3; (b) SEM image of as-prepared samples of CuO/In2O3 (CuO concentration = 3.5 wt%) and corresponding (c) TEM image; (d) Response of each sensor to 5 ppm H2S at different operating temperatures; (e) Selectivity of each sensor to 5 ppm H2S gas and other gases (5, 10, or 50 ppm) at 70 °C; (f) Schematics of carrier transportation and gas-sensing mechanism of the CuO/In2O3 heterostructure; (g) Energy level diagram of CuO/In2O3 heterostructure [88].
Ijerph 20 04388 g006
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Wei, H.; Zhang, H.; Song, B.; Yuan, K.; Xiao, H.; Cao, Y.; Cao, Q. Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review. Int. J. Environ. Res. Public Health 2023, 20, 4388. https://doi.org/10.3390/ijerph20054388

AMA Style

Wei H, Zhang H, Song B, Yuan K, Xiao H, Cao Y, Cao Q. Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review. International Journal of Environmental Research and Public Health. 2023; 20(5):4388. https://doi.org/10.3390/ijerph20054388

Chicago/Turabian Style

Wei, Huijie, Huiyan Zhang, Bing Song, Kaiping Yuan, Hongbin Xiao, Yunyi Cao, and Qi Cao. 2023. "Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review" International Journal of Environmental Research and Public Health 20, no. 5: 4388. https://doi.org/10.3390/ijerph20054388

APA Style

Wei, H., Zhang, H., Song, B., Yuan, K., Xiao, H., Cao, Y., & Cao, Q. (2023). Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review. International Journal of Environmental Research and Public Health, 20(5), 4388. https://doi.org/10.3390/ijerph20054388

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop