Advanced Photocatalytic Nanomaterials for Energy Conversion and Environmental Remediation

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Energy and Catalysis".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 29295

Special Issue Editors


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Guest Editor
School of Physics, Beihang University, Beijing 100191, China
Interests: first-principle calculations; materials for energy conversion and storage; low-dimesional materials

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Guest Editor
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
Interests: photo/electrocatalytic reactions; functional metal complexes

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Guest Editor
School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
Interests: photocatalysts; electrocatalysts; photoelectrocatalysts

Special Issue Information

Dear Colleagues,

With the rapid development of economy and society, the problem of energy shortage and environmental pollution is becoming more and more serious. Researchers worldwide have been exploring new technologies to effectively overcome the problems above. Photocatalytic technology is one of the most promising long-term solutions to directly utilize green solar energy to produce valuable chemical fuels and degrade pollutants. Therefore, the research of photocatalytic materials can promote the development of photocatalysis, which is of great significance in terms of energy and environment.

The purpose of this special issue is to collect the latest research results in the field of photocatalysts, both from a fundamental and applied perspective. The areas of focus for this special issue include: photocatalytic materials for water splitting, CO2 conversion, nitrogen fixation, pollutant degradation, and organic synthesis, first-principles calculation of photocatalytic materials, design and modification strategies of photocatalytic materials, analysis of photocatalytic principles, and characterization methods. Welcome to submit review or research papers on the preparation, properties, mechanism, and application of photocatalytic materials.

Prof. Dr. Junying Zhang
Prof. Yong Chen
Prof. Jungang Hou
Guest Editors

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Keywords

  • Photocatalytic materials
  • Hydrogen evolution
  • CO2 reduction
  • Nitrogen fixation
  • Pollutant degradation
  • Organic Synthesis
  • First-principles calculation
  • Photocatalytic principles
  • Characterization methods
  • Modification strategies

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Published Papers (12 papers)

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Editorial

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3 pages, 189 KiB  
Editorial
Advanced Photocatalytic Nanomaterials for Energy Conversion and Environmental Remediation
by Junying Zhang, Yong Chen and Jungang Hou
Nanomaterials 2023, 13(15), 2246; https://doi.org/10.3390/nano13152246 - 3 Aug 2023
Viewed by 1027
Abstract
With the rapid development of the economy and society, the problem of energy shortage and environmental pollution is receiving more and more attention [...] Full article

Research

Jump to: Editorial

15 pages, 4006 KiB  
Article
Hollow Spherical Pd/CdS/NiS with Carrier Spatial Separation for Photocatalytic Hydrogen Generation
by Xiao Wang, Fei Zhao, Nan Zhang, Wenli Wu and Yuhua Wang
Nanomaterials 2023, 13(8), 1326; https://doi.org/10.3390/nano13081326 - 10 Apr 2023
Cited by 3 | Viewed by 1740
Abstract
Inspired by the unique properties of the three-dimensional hollow nanostructures in the field of photocatalysis, as well as the combination of co-catalyst, porous hollow spherical Pd/CdS/NiS photocatalysts are prepared by stepwise synthesis. The results show that the Schottky junction between Pd and CdS [...] Read more.
Inspired by the unique properties of the three-dimensional hollow nanostructures in the field of photocatalysis, as well as the combination of co-catalyst, porous hollow spherical Pd/CdS/NiS photocatalysts are prepared by stepwise synthesis. The results show that the Schottky junction between Pd and CdS accelerates the transport of photogenerated electrons, while a p-n junction between NiS and CdS traps the photogenerated holes. As co-catalysts, the Pd nanoparticles and the NiS are loaded inside and outside the hollow CdS shell layer, respectively, which combines with the particular characteristic of the hollow structure, resulting in a spatial carrier separation effect. Under the synergy of the dual co-catalyst loading and hollow structure, the Pd/CdS/NiS has favorable stability. Its H2 production under visible light is significantly increased to 3804.6 μmol/g/h, representing 33.4 times more than that of pure CdS. The apparent quantum efficiency is 0.24% at 420 nm. A feasible bridge for the development of efficient photocatalysts is offered by this work. Full article
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12 pages, 3054 KiB  
Article
In Situ Photodeposition of Cobalt Phosphate (CoHxPOy) on CdIn2S4 Photocatalyst for Accelerated Hole Extraction and Improved Hydrogen Evolution
by Jiachen Xu, Qinran Li, Dejian Sui, Wei Jiang, Fengqi Liu, Xiuquan Gu, Yulong Zhao, Pengzhan Ying, Liang Mao, Xiaoyan Cai and Junying Zhang
Nanomaterials 2023, 13(3), 420; https://doi.org/10.3390/nano13030420 - 19 Jan 2023
Cited by 8 | Viewed by 2107
Abstract
The ternary metal sulfide CdIn2S4 (CIS) has great application potential in solar-to-hydrogen conversion due to its suitable band gap, good stability and low cost. However, the photocatalytic hydrogen (H2) evolution performance of CIS is severely limited by the [...] Read more.
The ternary metal sulfide CdIn2S4 (CIS) has great application potential in solar-to-hydrogen conversion due to its suitable band gap, good stability and low cost. However, the photocatalytic hydrogen (H2) evolution performance of CIS is severely limited by the rapid electron–hole recombination originating from the slow photogenerated hole transfer kinetics. Herein, by simply depositing cobalt phosphate (CoHxPOy, noted as Co-Pi), a non-precious co-catalyst, an efficient pathway for accelerating the hole transfer process and subsequently promoting the H2 evolution reaction (HER) activity of CIS nanosheets is developed. X-ray photoelectron spectroscopy (XPS) reveals that the Co atoms of Co-Pi preferentially combine with the unsaturated S atoms of CIS to form Co-S bonds, which act as channels for fast hole extraction from CIS to Co-Pi. Electron paramagnetic resonance (EPR) and time-resolved photoluminescence (TRPL) showed that the introduction of Co-Pi on ultrathin CIS surface not only increases the probability of photogenerated holes arriving the catalyst surface, but also prolongs the charge carrier’s lifetime by reducing the recombination of electrons and holes. Therefore, Co-Pi/CIS exhibits a satisfactory photocatalytic H2 evolution rate of 7.28 mmol g−1 h−1 under visible light, which is superior to the pristine CIS (2.62 mmol g−1 h−1) and Pt modified CIS (3.73 mmol g−1 h−1). Full article
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17 pages, 4263 KiB  
Article
Plasma Ag-Modified α-Fe2O3/g-C3N4 Self-Assembled S-Scheme Heterojunctions with Enhanced Photothermal-Photocatalytic-Fenton Performances
by Yawei Xiao, Bo Yao, Zhezhe Wang, Ting Chen, Xuechun Xiao and Yude Wang
Nanomaterials 2022, 12(23), 4212; https://doi.org/10.3390/nano12234212 - 27 Nov 2022
Cited by 14 | Viewed by 2693
Abstract
Low spectral utilization and charge carrier compounding limit the application of photocatalysis in energy conversion and environmental purification, and the rational construction of heterojunction is a promising strategy to break this bottleneck. Herein, we prepared surface-engineered plasma Ag-modified α-Fe2O3/g-C [...] Read more.
Low spectral utilization and charge carrier compounding limit the application of photocatalysis in energy conversion and environmental purification, and the rational construction of heterojunction is a promising strategy to break this bottleneck. Herein, we prepared surface-engineered plasma Ag-modified α-Fe2O3/g-C3N4 S-Scheme heterojunction photothermal catalysts by electrostatic self-assembly and light deposition strategy. The local surface plasmon resonance effect induced by Ag nanoparticles broadens the spectral response region and produces significant photothermal effects. The temperature of Ag/α-Fe2O3/g-C3N4 powder is increased to 173 °C with irradiation for 90 s, ~3.2 times higher than that of the original g-C3N4. The formation of 2D/2D structured S-Scheme heterojunction promotes rapid electron-hole transfer and spatial separation. Ternary heterojunction construction leads to significant enhancement of photocatalytic performance of Ag/α-Fe2O3/g-C3N4, the H2 photocatalytic generation rate up to 3125.62 µmol g−1 h−1, which is eight times higher than original g-C3N4, and the photocatalytic degradation rate of tetracycline to reach 93.6%. This thermally assisted photocatalysis strategy improves the spectral utilization of conventional photocatalytic processes and provides new ideas for the practical application of photocatalysis in energy conversion and environmental purification. Full article
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18 pages, 80536 KiB  
Article
Facilitated Photocatalytic Degradation of Rhodamine B over One-Step Synthesized Honeycomb-Like BiFeO3/g-C3N4 Catalyst
by Haoran Cui, Zhipeng Wang, Guoqiang Cao, Yiwan Wu, Jian Song, Yu Li, Le Zhang, Jiliang Mu and Xiujian Chou
Nanomaterials 2022, 12(22), 3970; https://doi.org/10.3390/nano12223970 - 10 Nov 2022
Cited by 3 | Viewed by 1604
Abstract
In the present work, a facile one-step methodology was used to synthesize honeycomb-like BiFeO3/g-C3N4 composites, where the well-dispersed BiFeO3 strongly interacted with the hg-C3N4. The 10BiFeO3/hg-C3N4 could completely [...] Read more.
In the present work, a facile one-step methodology was used to synthesize honeycomb-like BiFeO3/g-C3N4 composites, where the well-dispersed BiFeO3 strongly interacted with the hg-C3N4. The 10BiFeO3/hg-C3N4 could completely degrade RhB under visible light illumination within 60 min. The degradation rate constant was remarkably improved and approximately three times and seven times that of pristine hg-C3N4 and BiFeO3, respectively. This is ascribed to the following factors: (1) the unique honeycomb-like morphology facilitates the diffusion of the reactants and effectively improves the utilization of light energy by multiple reflections of light; (2) the charged dye molecules can be tightly bound to the spontaneous polarized BiFeO3 surface to form the Stern layer; (3) the Z-scheme heterojunction and the ferroelectric synergistically promoted the efficient separation and migration of the photogenerated charges. This method can synchronously tune the micro-nano structure, surface property, and internal field construction for g-C3N4-based photocatalysts, exhibiting outstanding potential in environmental purification. Full article
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21 pages, 5157 KiB  
Article
The Effect of La3+ on the Methylene Blue Dye Removal Capacity of the La/ZnTiO3 Photocatalyst, a DFT Study
by Ximena Jaramillo-Fierro, Guisella Cuenca and John Ramón
Nanomaterials 2022, 12(18), 3137; https://doi.org/10.3390/nano12183137 - 10 Sep 2022
Cited by 13 | Viewed by 1824
Abstract
Theoretically, lanthanum can bond with surface oxygens of ZnTiO3 to form La-O-Ti bonds, resulting in the change of both the band structure and the electron state of the surface. To verify this statement, DFT calculations were performed using a model with a [...] Read more.
Theoretically, lanthanum can bond with surface oxygens of ZnTiO3 to form La-O-Ti bonds, resulting in the change of both the band structure and the electron state of the surface. To verify this statement, DFT calculations were performed using a model with a dispersed lanthanum atom on the surface (101) of ZnTiO3. The negative heat segmentation values obtained suggest that the incorporation of La on the surface of ZnTiO3 is thermodynamically stable. The bandgap energy value of La/ZnTiO3 (2.92 eV) was lower than that of ZnTiO3 (3.16 eV). TDOS showed that the conduction band (CB) and the valence band (VB) energy levels of La/ZnTiO3 are denser than those of ZnTiO3 due to the participation of hybrid levels composed mainly of O2p and La5d orbitals. From the PDOSs, Bader’s charge analysis, and ELF function, it was established that the La-O bond is polar covalent. MB adsorption on La/ZnTiO3 (−200 kJ/mol) was more favorable than on ZnTiO3 (−85 kJ/mol). From the evidence of this study, it is proposed that the MB molecule first is adsorbed on the surface of La/ZnTiO3, and then the electrons in the VB of La/ZnTiO3 are photoexcited to hybrid levels, and finally, the MB molecule oxidizes into smaller molecules. Full article
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16 pages, 4695 KiB  
Article
Ag3PO4-Deposited TiO2@Ti3C2 Petals for Highly Efficient Photodecomposition of Various Organic Dyes under Solar Light
by Ngoc Tuyet Anh Nguyen and Hansang Kim
Nanomaterials 2022, 12(14), 2464; https://doi.org/10.3390/nano12142464 - 18 Jul 2022
Cited by 11 | Viewed by 2423
Abstract
Two-dimensional Ti3C2 MXenes can be used to fabricate hierarchical TiO2 nanostructures that are potential photocatalysts. In this study, the photodecomposition of organic dyes under solar light was investigated using flower-like TiO2@Ti3C2, deposited using [...] Read more.
Two-dimensional Ti3C2 MXenes can be used to fabricate hierarchical TiO2 nanostructures that are potential photocatalysts. In this study, the photodecomposition of organic dyes under solar light was investigated using flower-like TiO2@Ti3C2, deposited using narrow bandgap Ag3PO4. The surface morphology, crystalline structure, surface states, and optical bandgap properties were determined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption analysis, and UV-Vis diffuse reflectance spectroscopy (UV-DRS). Overall, Ag3PO4-deposited TiO2@Ti3C2, referred to as Ag3PO4/TiO2@Ti3C2, demonstrated the best photocatalytic performance among the as-prepared samples, including TiO2@Ti3C2, pristine Ag3PO4, and Ag3PO4/TiO2 P25. Organic dyes, such as rhodamine B (RhB), methylene blue (MB), crystal violet (CV), and methylene orange (MO), were efficiently degraded by Ag3PO4/TiO2@Ti3C2. The significant enhancement of photocatalysis by solar light irradiation was attributed to the efficient deposition of Ag3PO4 nanoparticles on flower-like TiO2@Ti3C2 with the efficient separation of photogenerated e-/h+ pairs, high surface area, and extended visible-light absorption. Additionally, the small size of Ag3PO4 deposition (ca. 4–10 nm diameter) reduces the distance between the core and the surface of the composite, which inhibits the recombination of photogenerated charge carriers. Free radical trapping tests were performed, and a photocatalytic mechanism was proposed to explain the synergistic photocatalysis of Ag3PO4/TiO2@Ti3C2 under solar light. Full article
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16 pages, 9289 KiB  
Article
N, P Self-Doped Porous Carbon Material Derived from Lotus Pollen for Highly Efficient Ethanol–Water Mixtures Photocatalytic Hydrogen Production
by Jing-Wen Zhou, Xia Jiang, Yan-Xin Chen, Shi-Wei Lin and Can-Zhong Lu
Nanomaterials 2022, 12(10), 1744; https://doi.org/10.3390/nano12101744 - 20 May 2022
Cited by 8 | Viewed by 1910
Abstract
Porous biochar materials prepared with biomass as a precursor have received widespread attention. In this work, lotus pollen (LP) was used as the carbon source, a variety of the pollen carbon photocatalyst were prepared by a two-step roasting method. A series of characterizations [...] Read more.
Porous biochar materials prepared with biomass as a precursor have received widespread attention. In this work, lotus pollen (LP) was used as the carbon source, a variety of the pollen carbon photocatalyst were prepared by a two-step roasting method. A series of characterizations were carried out on the prepared samples, and it was found that the average particle size was about 40 μm. They also exhibit a typical amorphous carbon structure and a porous structure with a network-like interconnected surface. The photocatalytic hydrogen production performances of lotus pollen carbon (LP-C) and commercial carbon black (CB) were measured under the full spectrum illumination. LP-C-600 showed the best hydrogen production performance (3.5 μmol·g−1·h−1). In addition, the photoelectrochemical (PEC) measurement results confirmed that the LP-C materials show better incident photon-current efficiency (IPCE) performance than the CB materials in the neutral electrolyte. This is because the unique surface wrinkling, hierarchical porous structure, and the N, P self-doping behavior of the LP-C samples are able to improve the light utilization efficiency and the carrier separation/transfer efficiency, thereby further improving the overall hydrogen production efficiency. Full article
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14 pages, 4655 KiB  
Article
Binary Type-II Heterojunction K7HNb6O19/g-C3N4: An Effective Photocatalyst for Hydrogen Evolution without a Co-Catalyst
by Qi Song, Shiliang Heng, Wenbin Wang, Huili Guo, Haiyan Li and Dongbin Dang
Nanomaterials 2022, 12(5), 849; https://doi.org/10.3390/nano12050849 - 2 Mar 2022
Cited by 13 | Viewed by 3358
Abstract
The binary type-II heterojunction photocatalyst containing g-C3N4 and polyoxoniobate (PONb, K7HNb6O19) with excellent H2 production activity was synthesized by decorating via a facile hydrothermal method for the first time. The as-fabricated Nb–CN-0.4 composite [...] Read more.
The binary type-II heterojunction photocatalyst containing g-C3N4 and polyoxoniobate (PONb, K7HNb6O19) with excellent H2 production activity was synthesized by decorating via a facile hydrothermal method for the first time. The as-fabricated Nb–CN-0.4 composite displayed a maximum hydrogen evolution rate of 359.89 µmol g−1 h−1 without a co-catalyst under the irradiation of a 300 W Xenon Lamp, which is the highest among those of the binary PONb-based photocatalytic materials reported. The photophysical and photochemistry analyses indicated that the hydrogen evolution performance could be attributed to the formation of a type-II heterojunction, which could not only accelerate the transfer of photoinduced interfacial charges, but also effectively inhibit the recombination of electrons and holes. This work could provide a useful reference to develop an inexpensive and efficient photocatalytic system based on PONb towards H2 production. Full article
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10 pages, 2261 KiB  
Communication
Enhancing Photocatalytic Hydrogen Production of g-C3N4 by Selective Deposition of Pt Cocatalyst
by Yang Li, Yue Lu, Zhaoyu Ma, Lianqing Dong, Xiaofang Jia and Junying Zhang
Nanomaterials 2021, 11(12), 3266; https://doi.org/10.3390/nano11123266 - 30 Nov 2021
Cited by 12 | Viewed by 2808
Abstract
Graphitic carbon nitride (g-C3N4) has been widely studied as a photocatalyst for the splitting of water to produce hydrogen. In order to solve the problems of limited number of active sites and serious recombination rate of charge-carriers, noble metals [...] Read more.
Graphitic carbon nitride (g-C3N4) has been widely studied as a photocatalyst for the splitting of water to produce hydrogen. In order to solve the problems of limited number of active sites and serious recombination rate of charge-carriers, noble metals are needed as cocatalysts. Here, we selectively anchored Pt nanoparticles (NPs) to specific nitrogen species on the surface of g-C3N4 via heat treatment in argon–hydrogen gas mixture, thus achieving g-C3N4 photocatalyst anchored by highly dispersed homogeneous Pt NPs with the co-existed metallic Pt0 and Pt2+ species. The synergistic effect of highly dispersed metallic Pt0 and Pt2+ species makes the catalyst exhibit excellent photocatalytic performance. Under the full-spectrum solar light irradiation, the photocatalytic hydrogen production rate of the photocatalyst is up to 18.67 mmol·g−1·h−1, which is 5.1 times of the catalyst prepared by non-selective deposition of Pt NPs. Full article
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16 pages, 3908 KiB  
Article
Defective Black TiO2: Effects of Annealing Atmospheres and Urea Addition on the Properties and Photocatalytic Activities
by Xu Zhang, Min Cai, Naxin Cui, Guifa Chen, Guoyan Zou and Li Zhou
Nanomaterials 2021, 11(10), 2648; https://doi.org/10.3390/nano11102648 - 9 Oct 2021
Cited by 14 | Viewed by 2247
Abstract
A series of black TiO2 with and without the addition of urea were successfully prepared using a simple one-step synthetic method by calcination under different atmospheres (vacuum, He, or N2). The physicochemical, optical, and light-induced charge transfer properties of the [...] Read more.
A series of black TiO2 with and without the addition of urea were successfully prepared using a simple one-step synthetic method by calcination under different atmospheres (vacuum, He, or N2). The physicochemical, optical, and light-induced charge transfer properties of the as-prepared samples were characterized by various techniques. It was found that a vacuum atmosphere was more beneficial for the formation of oxygen vacancies (OVs) than the inert gases (He and N2) and the addition of urea-inhibited OVs formation. The samples annealed in the vacuum condition exhibited better visible-light adsorption abilities, narrower bandgaps, higher photo-induced charge separation efficiency, and lower recombination rates. Hydroxyl radicals (·OH) were the dominant oxidative species in the samples annealed under a vacuum. Finally, the samples annealed under vacuum conditions displayed higher photocatalytic activity for methylene blue (MB) degradation than the samples annealed under He or N2. Based on the above, this study provides new insights into the effects of annealing atmospheres and urea addition on the properties of black TiO2. Full article
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15 pages, 3479 KiB  
Article
Photodehydrogenation of Ethanol over Cu2O/TiO2 Heterostructures
by Congcong Xing, Yu Zhang, Yongpeng Liu, Xiang Wang, Junshan Li, Paulina R. Martínez-Alanis, Maria Chiara Spadaro, Pablo Guardia, Jordi Arbiol, Jordi Llorca and Andreu Cabot
Nanomaterials 2021, 11(6), 1399; https://doi.org/10.3390/nano11061399 - 25 May 2021
Cited by 14 | Viewed by 4201
Abstract
The photodehydrogenation of ethanol is a sustainable and potentially cost-effective strategy to produce hydrogen and acetaldehyde from renewable resources. The optimization of this process requires the use of highly active, stable and selective photocatalytic materials based on abundant elements and the proper adjustment [...] Read more.
The photodehydrogenation of ethanol is a sustainable and potentially cost-effective strategy to produce hydrogen and acetaldehyde from renewable resources. The optimization of this process requires the use of highly active, stable and selective photocatalytic materials based on abundant elements and the proper adjustment of the reaction conditions, including temperature. In this work, Cu2O-TiO2 type-II heterojunctions with different Cu2O amounts are obtained by a one-pot hydrothermal method. The structural and chemical properties of the produced materials and their activity toward ethanol photodehydrogenation under UV and visible light illumination are evaluated. The Cu2O-TiO2 photocatalysts exhibit a high selectivity toward acetaldehyde production and up to tenfold higher hydrogen evolution rates compared to bare TiO2. We further discern here the influence of temperature and visible light absorption on the photocatalytic performance. Our results point toward the combination of energy sources in thermo-photocatalytic reactors as an efficient strategy for solar energy conversion. Full article
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