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21 pages, 9959 KiB

Open AccessArticle

One Material-Opposite Triboelectrification: Molecular Engineering Regulated Triboelectrification on Silica Surface to Enhance TENG Efficiency

by Mesude Zeliha Arkan, Zeynep Kinas, Eyup Yalcin, Emre Arkan, Faruk Özel, Abdulkerim Karabiber and Mirosław Chorążewski

Molecules 2023, 28(15), 5662; https://doi.org/10.3390/molecules28155662 - 26 Jul 2023

Cited by 3 | Viewed by 1358

Abstract

Molecular engineering is a unique methodology to take advantage of the electrochemical characteristics of materials that are used in energy-harvesting devices. Particularly in triboelectric nanogenerator (TENG) studies, molecular grafting on dielectric metal oxide surfaces can be regarded as a feasible way to alter [...] Read more.

Molecular engineering is a unique methodology to take advantage of the electrochemical characteristics of materials that are used in energy-harvesting devices. Particularly in triboelectric nanogenerator (TENG) studies, molecular grafting on dielectric metal oxide surfaces can be regarded as a feasible way to alter the surface charge density that directly affects the charge potential of triboelectric layers. Herein, we develop a feasible methodology to synthesize organic–inorganic hybrid structures with tunable triboelectric features. Different types of self-assembled monolayers (SAMs) with electron-donating and withdrawing groups have been used to modify metal oxide (MO) surfaces and to modify their charge density on the surface. All the synthetic routes for hybrid material production have been clearly shown and the formation of covalent bonds on the MO’s surface has been confirmed by XPS. The obtained hybrid structures were applied as dopants to distinct polymer matrices with various ratios and fiberization processes were carried out to the prepare opposite triboelectric layers. The formation of the fibers was analyzed by SEM, while their surface morphology and physicochemical features have been measured by AFM and a drop shape analyzer. The triboelectric charge potential of each layer after doping and their contribution to the TENG device’s parameters have been investigated. For each triboelectric layer, the best-performing tribopositive and tribonegative material combination was separately determined and then these opposite layers were used to fabricate TENG with the highest efficiency. A comparison of the device parameters with the reference indicated that the best tribopositive material gave rise to a 40% increase in the output voltage and produced 231 V, whereas the best tribonegative one led to a 33.3% rise in voltage and generated 220 V. In addition, the best device collected ~83% more charge than the reference device and came up with 250 V that corresponds to 51.5% performance enhancement. This approach paved the way by addressing the issue of how molecular engineering can be used to manipulate the triboelectric features of the same materials. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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17 pages, 2137 KiB

Open AccessArticle

Grafting of Crown Ether and Cryptand Macrocycles on Large Pore Stellate Mesoporous Silica for Sodium Cation Extraction

by Paula Duenas-Ramirez, Caroline Bertagnolli, Robin Weiss, Joëlle Bizeau, Loïc Jierry, Philippe Choquet, Ariane Zaloszyc, Sylvie Bégin-Colin and Damien Mertz

Molecules 2023, 28(12), 4622; https://doi.org/10.3390/molecules28124622 - 7 Jun 2023

Cited by 1 | Viewed by 2025

Abstract

Regulation of the sodium cations level in the case of renal failure diseases is a very challenging task for clinicians, and new pollutant extractors based on nanomaterials are emerging as potential treatments. In this work, we report different strategies for the chemical functionalization [...] Read more.

Regulation of the sodium cations level in the case of renal failure diseases is a very challenging task for clinicians, and new pollutant extractors based on nanomaterials are emerging as potential treatments. In this work, we report different strategies for the chemical functionalization of biocompatible large pore mesoporous silica, denoted stellate mesoporous silica (STMS), with chelating ligands able to selectively capture sodium. We address efficient methods to covalently graft highly chelating macrocycles onto STMS NPs such as crown ethers (CE) and cryptands (C221) through complementary carbodiimidation reactions. Regarding sodium capture in water, C221 cryptand-grafted STMS showed better capture efficiency than CE-STMS due to higher sodium atom chelation in the cryptand cage (Na⁺ coverage of 15.5% vs. 3.7%). The sodium selectivity was hence tested with C221 cryptand-grafted STMS in a multi-element aqueous solution (metallic cations with the same concentration) and in a solution mimicking peritoneal dialysis solution. Results obtained indicate that C221 cryptand-grafted STMS are relevant nanomaterials to extract sodium cations in such media and allow us to regulate their levels. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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16 pages, 4399 KiB

Open AccessArticle

Improvement in Corrosion Resistance and Interfacial Contact Resistance Properties of 316L Stainless Steel by Coating with Cr, Ti Co-Doped Amorphous Carbon Films in the Environment of the PEMFCs

by Baosen Mi, Quan Wang, Yuhao Xu, Ziwei Qin, Zhuo Chen and Hongbin Wang

Molecules 2023, 28(6), 2821; https://doi.org/10.3390/molecules28062821 - 21 Mar 2023

Cited by 2 | Viewed by 2630

Abstract

In order to obtain films with high corrosion resistance and excellent interfacial contact resistance (ICR) on 316L stainless steel used for bipolar plates in proton-exchange membrane fuel cells (PEMFCs), Cr, Ti co-doped amorphous carbon films were prepared on 316L stainless steel. The preparation [...] Read more.

In order to obtain films with high corrosion resistance and excellent interfacial contact resistance (ICR) on 316L stainless steel used for bipolar plates in proton-exchange membrane fuel cells (PEMFCs), Cr, Ti co-doped amorphous carbon films were prepared on 316L stainless steel. The preparation method for the coating was magnetron sputtering. The doping amount of the Ti element was controlled by a Cr target and a Ti target current. The change in the structure and properties of the coating after the change from Cr single-element doping to Cr and Ti co-doping was studied. The change rule of the structure and properties of the coating from Cr single-element doping to Cr and Ti co-doping was studied. An increase in the Ti content led to a decreased grain boundary, a flatter surface, and a higher sp²-hybridized carbon content. TiC and CrC nanocrystals were formed in the amorphous carbon structure together. The amorphous carbon films doped with Cr and Ti simultaneously achieved a low ICR and high corrosion resistance compared with single-Cr-doped amorphous carbon. The enhanced corrosion resistance was attributed to the decreasing grain boundary, the formation of the TiC crystal structure, and the smaller grain size. The best performance was obtained at a Ti target current of 2A. Compared with bare 316L stainless steel, the corrosion resistance of Cr, Ti co-doped amorphous carbon (I_corr = 5.7 × 10⁻⁸ A/cm², Ti-2 sample) was greatly improved. Because Ti doping increased the content of sp²-hybridized carbon in the coating, the contact resistance of the coating decreased. Moreover, the interfacial contact resistance was 3.1 mΩ·cm² in the Ti-2 sample, much lower than that of bare 316L stainless steel. After the potentiostatic polarization test, the coating still had excellent conductivity. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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18 pages, 10009 KiB

Open AccessArticle

In-Depth Insight into the Ag/CNQDs/g-C₃N₄ Photocatalytic Degradation of Typical Antibiotics: Influence Factor, Mechanism and Toxicity Evaluation of Intermediates

by Chen Li, Tianyi Sun, Guohui Yi, Dashuai Zhang, Yan Zhang, Xiaoxue Lin, Jinrui Liu, Zaifeng Shi and Qiang Lin

Molecules 2023, 28(4), 1597; https://doi.org/10.3390/molecules28041597 - 7 Feb 2023

Cited by 5 | Viewed by 1877

Abstract

In this paper, the photocatalytic degradation efficiency of typical antibiotics (norfloxacin (NOR), sulfamethoxazole (SMX) and tetracycline hydrochloride (TCH)) by Ag/CNQDs/g-C₃N₄ under visible light irradiation was studied. Various strategies were applied to characterize the morphology, structure and photochemical properties of the [...] Read more.

In this paper, the photocatalytic degradation efficiency of typical antibiotics (norfloxacin (NOR), sulfamethoxazole (SMX) and tetracycline hydrochloride (TCH)) by Ag/CNQDs/g-C₃N₄ under visible light irradiation was studied. Various strategies were applied to characterize the morphology, structure and photochemical properties of the Ag/CNQDs/g-C₃N₄ composites. The superior photocatalytic activity of Ag/CNQDs/g-C₃N₄ was attributed to the wide light response range and the enhancement of interfacial charge transfer. At the same time, the effect of the influence factors (pH, Humic acid (HA) and coexisting ions) on the antibiotics degradation were also investigated. Furthermore, the electron spin resonance (ESR) technology, free radical quenching experiments, LC/MS and DFT theoretical calculations were applied to predict and identify the active groups and intermediates during the photocatalytic degradation process. In addition, Ag/CNQDs/g-C₃N₄ exhibited the obvious antibacterial effect to Escherichia coli due to the addition of Ag NPs. This study develops a new way for the removal of emerging antibiotic pollution from wastewaters. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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15 pages, 6543 KiB

Open AccessArticle

Zinc Vanadate (Zn₃V₂O₈) Immobilized Multiwall Carbon Nanotube (MWCNT) Heterojunction as an Efficient Photocatalyst for Visible Light Driven Hydrogen Production

by Fahad A. Alharthi, Alanood Sulaiman Ababtain, Hamdah S. Alanazi, Alanoud Abdullah Alshayiqi and Imran Hasan

Molecules 2023, 28(3), 1362; https://doi.org/10.3390/molecules28031362 - 31 Jan 2023

Cited by 8 | Viewed by 3284

Abstract

Z-scheme photocatalytic reaction is considered an effective strategy to promote the photogenerated electron-hole separation for significantly improving the efficiency of photocatalytic hydrogen precipitation from splitting water. In this study, a heterojunction nanocomposite material based on Zn₃V₂O₈ (ZV) with [...] Read more.

Z-scheme photocatalytic reaction is considered an effective strategy to promote the photogenerated electron-hole separation for significantly improving the efficiency of photocatalytic hydrogen precipitation from splitting water. In this study, a heterojunction nanocomposite material based on Zn₃V₂O₈ (ZV) with MWCNT was prepared by a hydrothermal process. The photocatalysts were characterized by X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), UV-visible absorption spectroscopy, and transmission electron microscopy (TEM) to understand crystal structure, morphology, and optical properties. The efficiency of the samples was evaluated for the photocatalytic H₂ production under visible solar radiation using water glycerol as a sacrificial reagent. The obtained results suggest that, between ZV and ZV@MWCNT, the latter shows higher efficiency for H₂ production. The maximum H₂ production efficiency was found to be 26.87 μmol g⁻¹ h⁻¹ for ZV and 99.55 μmol g⁻¹ h⁻¹ for ZV@MWCNT. The synergistic effect of MWCNT to ZV resulted in improving the efficiency of charges and light-absorbing capacity, resulting in enhanced H₂ production in the heterojunction nanocomposite material. The nanocomposite was stable and highly efficient for H₂ production of six or more cycles. Based on the outcomes of this study, it can be observed that forming the heterojunction of individual nano systems could result in more efficient material for H₂ production under visible solar energy. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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12 pages, 2793 KiB

Open AccessArticle

Biochar-Based Photothermal Hydrogel for Efficient Solar Water Purification

by Liang Wang, Jilei Wei, Kun Fang, Chen Zhou and Shengyang Yang

Molecules 2023, 28(3), 1157; https://doi.org/10.3390/molecules28031157 - 24 Jan 2023

Cited by 4 | Viewed by 2808

Abstract

The development of technology for solar interface evaporation has a significant meaning for the sustainable use of water resources in remote regions. However, establishing a solar evaporator with a high evaporation rate and favorable water treatment capabilities remains challenging. In this work, we [...] Read more.

The development of technology for solar interface evaporation has a significant meaning for the sustainable use of water resources in remote regions. However, establishing a solar evaporator with a high evaporation rate and favorable water treatment capabilities remains challenging. In this work, we reported a silver nanoparticle (AgNP)@carbonized cattail (CC)/polyvinyl alcohol (PVA) composite hydrogel (ACPH) membrane. Because of the successfully loaded AgNPs, which have a photothermal synergy with the CC, the ACPH-10 membrane obtained an excellent photothermal conversion performance. Additionally, the hydrophilicity of the ACPH-10 membrane ensures a sustainable water supply which is necessary for the improvement of the evaporation rate. Therefore, the ACPH-10 membrane achieves an evaporation rate of 1.66 kg m⁻² h⁻¹ and an efficiency of 88.0%, attributed to the remarkable photothermal conversion and water transmission. More importantly, the membrane exhibits superior purification ability in a variety of sewage. Pollutant removal rates in heavy metal and organic dye sewage have exceeded 99.8%. As a result, the ACPH membrane holds great promise for wastewater recovery and seawater desalination, which can aid in resolving the water crisis issue. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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19 pages, 6455 KiB

Open AccessArticle

Ecofriendly Green Synthesis of Copper (II) Oxide Nanoparticles Using Corchorus olitorus Leaves (Molokhaia) Extract and Their Application for the Environmental Remediation of Direct Violet Dye via Advanced Oxidation Process

by Reham O. Aljedaani, Samia A. Kosa and Mohamed Abdel Salam

Molecules 2023, 28(1), 16; https://doi.org/10.3390/molecules28010016 - 20 Dec 2022

Cited by 14 | Viewed by 2298

Abstract

In this research, copper (II) oxide nanoparticles were prepared by an ecofriendly green method using the extract of corchorus olitorus leaves (Molokhaia) as a surfactant, capping and anti-agglomeration agent. The ecofriendly green CuO NPs were characterized using different chemical and physical techniques and [...] Read more.

In this research, copper (II) oxide nanoparticles were prepared by an ecofriendly green method using the extract of corchorus olitorus leaves (Molokhaia) as a surfactant, capping and anti-agglomeration agent. The ecofriendly green CuO NPs were characterized using different chemical and physical techniques and the results confirmed the formation of monoclinic tenorite CuO nanoparticles with an average particle size of 12 nm and BET surface area of 11.1 m²/g. The eco-friendly green CuO NPs were used in environmental remediation for the efficient catalytic degradation of direct violet dye via advanced oxidation process (AOP) in presence of H₂O₂. The impact of AOP environmental parameters affecting the degradation process was investigated. Moreover, the catalytic degradation of the direct violet dye using the ecofriendly green CuO NPs was studied kinetically and thermodynamically and the results showed that the catalytic degradation process agreed well with the pseudo-second-order kinetic model and the process was spontaneous and endothermic in nature. Finally, high catalytic degradation of the direct violet dye was observed when the eco-friendly prepared green CuO NPs were placed in real water samples. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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13 pages, 3963 KiB

Open AccessArticle

Electroplating Cobalt Films on Silicon Nanostructures for Sensing Molecules

by Chihyang Chen, Zhe Kan, Zibo Wang, Haibin Huo and Mengyan Shen

Molecules 2022, 27(23), 8440; https://doi.org/10.3390/molecules27238440 - 2 Dec 2022

Cited by 1 | Viewed by 1739

Abstract

In this study, we electroplated Co and Cu on nano-spiked silicon substrates that were treated with femtosecond laser irradiations. With energy-dispersive X-ray (EDX) analysis by a scanning electron microscope (SEM), it was found that both Co and Cu are primarily coated on the [...] Read more.

In this study, we electroplated Co and Cu on nano-spiked silicon substrates that were treated with femtosecond laser irradiations. With energy-dispersive X-ray (EDX) analysis by a scanning electron microscope (SEM), it was found that both Co and Cu are primarily coated on the spike surfaces without changing the morphology of the nanospikes. We also found that nanoscale bridges were formed, connecting the Co-coated silicon spikes. The formation of these bridges was studied and optimized through a series of time-controlled electroplating and oxidizing processes. The bridges are related to the oxidation of Co in the air. When it is irradiated with visible light, this special structure has shown a capability of interactions with carbon monoxide and carbon dioxide molecules. The electroplated cobalt may be used for gas sensors. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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19 pages, 3828 KiB

Open AccessArticle

Cross-Linked Ionic Liquid Polymer for the Effective Removal of Ionic Dyes from Aqueous Systems: Investigation of Kinetics and Adsorption Isotherms

by A. Vijaya Bhaskar Reddy, Rehan Rafiq, Aqeel Ahmad, Abdulhalim Shah Maulud and Muhammad Moniruzzaman

Molecules 2022, 27(22), 7775; https://doi.org/10.3390/molecules27227775 - 11 Nov 2022

Cited by 8 | Viewed by 1967

Abstract

In the current study, we have synthesized an imidazolium based cross-linked polymer, namely, 1-vinyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide (poly[veim][Tf₂N]-TRIM) using trimethylolpropane trimethacrylate as cross linker, and demonstrated its efficiency for the removal of two extensively used ionic dyes—methylene blue and orange-II—from aqueous systems. The [...] Read more.

In the current study, we have synthesized an imidazolium based cross-linked polymer, namely, 1-vinyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide (poly[veim][Tf₂N]-TRIM) using trimethylolpropane trimethacrylate as cross linker, and demonstrated its efficiency for the removal of two extensively used ionic dyes—methylene blue and orange-II—from aqueous systems. The detailed characterization of the synthesized poly[veim][Tf₂N]-TRIM was performed with the help of ¹H NMR, TGA, FT-IR and FE-SEM analysis. The concentration of dyes in aqueous samples before and after the adsorption process was measured using an UV-vis spectrophotometer. The process parameters were optimised, and highest adsorption was obtained at a solution pH of 7.0, adsorbent dosage of 0.75 g/L, contact time of 7 h and dye concentrations of 100 mg/L and 5.0 mg/L for methylene blue and orange-II, respectively. The adsorption kinetics for orange-II and methylene blue were well described by pseudo-first-order and pseudo–second-order models, respectively. Meanwhile, the process of adsorption was best depicted by Langmuir isotherms for both the dyes. The highest monolayer adsorption capacities for methylene blue and orange-II were found to be 1212 mg/g and 126 mg/g, respectively. Overall, the synthesized cross-linked poly[veim][Tf₂N]-TRIM effectively removed the selected ionic dyes from aqueous samples and provided >90% of adsorption efficiency after four cycles of adsorption. A possible adsorption mechanism between the synthesised polymeric adsorbent and proposed dyes is presented. It is further suggested that the proposed ionic liquid polymer adsorbent could effectively remove other ionic dyes and pollutants from contaminated aqueous systems. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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10 pages, 3859 KiB

Open AccessArticle

Responsive Ag@NiCo₂O₄ Nanowires Anchored on N-Doped Carbon Cloth as Array Electrodes for Nonenzymatic Glucose Sensing

by Li Wang, Xiaowei Lv, Lei Zhang, Yanli Fang, Hui Wang and Jianwei Ren

Molecules 2022, 27(22), 7745; https://doi.org/10.3390/molecules27227745 - 10 Nov 2022

Viewed by 1407

Abstract

The development of responsive materials in a predictable manner is high on the list of the material industry’s trends. In this work, responsive Ag@NiCo₂O₄ nanowires were, firstly, anchored on N-doped carbon cloth (NC) and, then, employed as array electrodes for [...] Read more.

The development of responsive materials in a predictable manner is high on the list of the material industry’s trends. In this work, responsive Ag@NiCo₂O₄ nanowires were, firstly, anchored on N-doped carbon cloth (NC) and, then, employed as array electrodes for a nonenzymatic glucose-sensing application. The results showed that the highly conductive NiCo₂O₄ nanowires supported Ag nanoparticles and exhibited high conductivity and electrocatalytic properties. The fully exposed crystalline planes of Ag nanoparticles provided more active surface sites. As a result, the assembled Ag@NiCo₂O₄-NC electrodes for the glucose-sensing evaluation delivered a selectivity of 2803 μA mM⁻¹ cm⁻² and a detection limit of 1.065 μM, which outperformed the literature-reported Ag- and NiCo₂O₄-based glucose-sensing catalysts. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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13 pages, 3499 KiB

Open AccessArticle

Design and Preparation of NiFe₂O₄@FeOOH Composite Electrocatalyst for Highly Efficient and Stable Oxygen Evolution Reaction

by Tian-Tian Li, Bu-Yan Shi, Li-Wen Jiang, Jin-Fan Zheng and Jian-Jun Wang

Molecules 2022, 27(21), 7438; https://doi.org/10.3390/molecules27217438 - 1 Nov 2022

Cited by 8 | Viewed by 2437

Abstract

Rational design and constructing earth-abundant electrocatalysts for efficient electrocatalytic water splitting is a crucial challenge. Herein, we report a simple and efficient one-step electrochemical synthetic route of the NiFe₂O₄@FeOOH composite electrocatalyst for the oxygen evolution reaction. The unique morphology [...] Read more.

Rational design and constructing earth-abundant electrocatalysts for efficient electrocatalytic water splitting is a crucial challenge. Herein, we report a simple and efficient one-step electrochemical synthetic route of the NiFe₂O₄@FeOOH composite electrocatalyst for the oxygen evolution reaction. The unique morphology of the NiFe₂O₄ nanoflowers loaded on FeOOH nanosheets allows more active sites to be exposed and promote charge transfer as well as gas release, and the resulting electrode enables a current density of 10 mA cm⁻² at a low overpotential of 255 mV with outstanding stability at a current density of 100 mA cm⁻² for 300 h. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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17 pages, 13191 KiB

Open AccessArticle

A Novel Nanocomposite Based on Triazine Based Covalent Organic Polymer Blended with Porous g-C₃N₄ for Photo Catalytic Dye Degradation of Rose Bengal and Fast Green

by Nachimuthu Venkatesh, Govindhasamy Murugadoss, Abdul Azeez Ashif Mohamed, Manavalan Rajesh Kumar, Shaik Gouse Peera and Pachagounder Sakthivel

Molecules 2022, 27(21), 7168; https://doi.org/10.3390/molecules27217168 - 23 Oct 2022

Cited by 14 | Viewed by 2284

Abstract

Metal free visible light active photocatalysts of covalent organic polymers (COPs) and polymeric graphitic carbon nitride (g-C₃N₄) are interesting porous catalysts that have enormous potential for application in organic pollutant degradation. Imine condensation for COPs, and thermal condensation for [...] Read more.

Metal free visible light active photocatalysts of covalent organic polymers (COPs) and polymeric graphitic carbon nitride (g-C₃N₄) are interesting porous catalysts that have enormous potential for application in organic pollutant degradation. Imine condensation for COPs, and thermal condensation for g-C₃N₄ were used to produce the catalysts. FT-IR, Raman, NMR, UV-Vis Spectroscopy, X-ray diffraction, and scanning electron microscopy studies were used to investigate the structural, optical, and morphological features of the metal free catalysts. We have constructed COPs with a π-electron deficient (Lewis acidic) triazine core and π -electron rich (Lewis basic) naphthalene and anthraquinone rings coupled by -O and -N donors in this study. Furthermore, the prepared Bulk-g-C₃N₄ (B-GCN) was converted to porous g-C₃N₄ (P-GCN) using a chemical oxidation process, and the generated P-GCN was efficiently mixed with the COP to create a novel nanocomposite for photocatalytic application. Using the anthraquinone-based COP and P-GCN (1:1 ratio, PA-GCN) catalyst, the highest photodegradation efficiencies for the polymeric graphitic carbon nitride of 88.2% and 82.3% were achieved using the Fast green (FG) and Rose bengal (RB) dyes, respectively. The rate constant values of 0.032 and 0.024/min were determined for FG and RB degradation, respectively. Higher activity may be related to the incorporation of COP and PA-GCN, which act significantly well in higher visible light absorption, have superior reactive oxygen generation (ROS), and demonstrate an excellent pollutant–catalyst interaction. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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19 pages, 5308 KiB

Open AccessArticle

Biowaste-Derived, Highly Efficient, Reusable Carbon Nanospheres for Speedy Removal of Organic Dyes from Aqueous Solutions

by Bhavya Krishnappa, Vinay S. Bhat, Vimala Ancy, Jyotsna Clemi Joshi, Jyothi M. S, Maya Naik and Gurumurthy Hegde

Molecules 2022, 27(20), 7017; https://doi.org/10.3390/molecules27207017 - 18 Oct 2022

Cited by 14 | Viewed by 2013

Abstract

The current work explores the adsorptive efficiency of carbon nanospheres (CNSs) derived from oil palm leaves (OPL) that are a source of biowaste. CNSs were synthesized at 400, 600, 800 and 1000 °C, and those obtained at 1000 °C demonstrated maximum removal efficiency [...] Read more.

The current work explores the adsorptive efficiency of carbon nanospheres (CNSs) derived from oil palm leaves (OPL) that are a source of biowaste. CNSs were synthesized at 400, 600, 800 and 1000 °C, and those obtained at 1000 °C demonstrated maximum removal efficiency of ~91% for malachite green (MG). Physicochemical and microscopic characteristics were analysed by FESEM, TEM, FTIR, Raman, TGA and XPS studies. The presence of surface oxygen sites and the porosity of CNSs synergistically influenced the speed of removal of MG, brilliant green (BG) and Congo red (CR) dyes. With a minimal adsorbent dosage (1 mg) and minimum contact time (10 min), and under different pH conditions, adsorption was efficient and cost-effective (nearly 99, 91 and 88% for BG, MG and CR, respectively). The maximum adsorption capacities of OPL-based CNSs for BG were 500 and 104.16 mg/g for MG and 25.77 mg/g for CR. Adsorption isotherms (Freundlich, Langmuir and Temkin) and kinetics models (pseudo-first-order, pseudo-second-order and Elovich) for the adsorption processes of all three dyes on the CNSs were explored in detail. BG and CR adsorption the Freundlich isotherm best, while MG showed a best fit to the Temkin model. Adsorption kinetics of all three dyes followed a pseudo-second-order model. A reusability study was conducted to evaluate the effectiveness of CNSs in removing the MG dye and showed ~92% efficiency even after several cycles. Highly efficient CNSs with surface oxygen groups and speedy removal of organic dyes within 10 min by CNSs are highlighted in this paper. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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15 pages, 3282 KiB

Open AccessReview

Shape-Persistent Dendrimers

by Yao-Chih Lu, Roberto Anedda and Long-Li Lai

Molecules 2023, 28(14), 5546; https://doi.org/10.3390/molecules28145546 - 20 Jul 2023

Cited by 5 | Viewed by 1299

Abstract

Dendrimers have a diverse and versatile morphology, frequently consisting of core, linking, and peripheral moieties. Dendrimers with flexible linkers, such as PAMAM, cannot retain the persistent shape of molecules, and this has been widely explored and reviewed previously; nevertheless, dendrimers with stiff linkers [...] Read more.

Dendrimers have a diverse and versatile morphology, frequently consisting of core, linking, and peripheral moieties. Dendrimers with flexible linkers, such as PAMAM, cannot retain the persistent shape of molecules, and this has been widely explored and reviewed previously; nevertheless, dendrimers with stiff linkers can preserve the persistent shape of the dendrimers, which has been reported considerably less. This review thus focuses on addressing shape-persistent dendrimers with rigid linking moieties discovered in recent years, i.e., from 2012 to 2023. Shape-persistent dendrimers with an interstitial gap between the dendritic frames in the solid state may or may not let the intramolecular void space be accessible for guest molecules, which largely depends on whether their peripheral groups are flexible or non-flexible. In this paper, eight articles on shape-persistent dendrimers with a flexible alkyl periphery, which may exhibit mesogenic phases upon thermal treatment, and eight articles on shape-persistent dendrimers with a non-flexible periphery, which may allow external ions, gases, or volatile organic compounds to access the interstitial gaps between dendritic frames, are reviewed. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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15 pages, 5030 KiB

Open AccessReview

Near-Infrared Light Driven ZnIn₂S₄-Based Photocatalysts for Environmental and Energy Applications: Progress and Perspectives

by Yi Cai, Fangxin Luo, Yujun Guo, Feng Guo, Weilong Shi and Shengtao Yang

Molecules 2023, 28(5), 2142; https://doi.org/10.3390/molecules28052142 - 24 Feb 2023

Cited by 13 | Viewed by 2463

Abstract

Zinc indium sulfide (ZnIn₂S₄), as a significant visible-light-responsive photocatalyst, has become a research hotspot to tackle energy demand and environmental issues owing to its excellent properties of high stability, easy fabrication, and remarkable catalytic activity. However, its drawbacks, including [...] Read more.

Zinc indium sulfide (ZnIn₂S₄), as a significant visible-light-responsive photocatalyst, has become a research hotspot to tackle energy demand and environmental issues owing to its excellent properties of high stability, easy fabrication, and remarkable catalytic activity. However, its drawbacks, including low utilization of solar light and fast photoinduced charge carriers, limit its applications. Promoting the response for near-infrared (NIR) light (~52% solar light) of ZnIn₂S₄-based photocatalysts is the primary challenge to overcome. In this review, various modulation strategies of ZnIn₂S₄ have been described, which include hybrid with narrow optical gap materials, bandgap engineering, up-conversion materials, and surface plasmon materials for enhanced NIR photocatalytic performance in the applications of hydrogen evolution, pollutants purification, and CO₂ reduction. In addition, the synthesis methods and mechanisms of NIR light-driven ZnIn₂S₄-based photocatalysts are summarized. Finally, this review presents perspectives for future development of efficient NIR photon conversion of ZnIn₂S₄-based photocatalysts. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials for Energy and Environment Applications)

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