Engineering Novel Heterojunctions for Photocatalytic Energy and Environmental Applications

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Photocatalysis".

Deadline for manuscript submissions: closed (20 August 2023) | Viewed by 6118

Special Issue Editors

Institute of Urban Environment, Chinese Academy of Sciences, 361024 Xiamen, China
Interests: metal nanoparticles; perovskites; photocatalysis; H2 evolution; selective organic transformations; CO2 reduction
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Guest Editor
College of Chemistry and Materials, Quanzhou Normal University, Quanzhou 362000, China
Interests: semiconductor nanomaterials; catalysis; H2 evolution; selective organic synthesis
Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
Interests: single-atom catalyst; covalent organic frameworks; CO2 photoreduction; photo-Fenton; advanced oxidation process

Special Issue Information

Dear Colleagues,

With the proliferation of industrialization and urbanization, resource depletion and environmental pollution have emerged as two major problems to humans. In view of the abundant solar energy, semiconductor-based photocatalysis has attracted considerable research attention worldwide for addressing energy and environmental challenges. Therefore, various photocatalysts, such as TiO2 and C3N4, have been fabricated and developed for energy production and environmental remediation. However, single-phase photocatalysts generally exhibit low catalytic efficiency due to the high photogenic carrier recombination rate and limited light absorption. To overcome those drawbacks and achieve high photocatalytic performance, the rational design and fabrication of heterojunction photocatalysts, such as semiconductor–semiconductor heterojunction, semiconductor–metal heterojunction, and multicomponent heterojunction, have been widely demonstrated to efficiently improve the photocatalytic activity of single-phase photocatalysts. This Special Issue is intended to provide an overview of the most common, purely semiconductor-based heterojunction composite photocatalysts for energy production and environmental remediation.

Dr. Bo Weng
Prof. Dr. Xiaoyang Pan
Dr. Bin Han
Guest Editors

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Keywords

  • semiconductor
  • heterojunction
  • photocatalysis
  • energy evolution
  • environmental remediation

Published Papers (5 papers)

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Research

14 pages, 1855 KiB  
Article
Construction of Palladium Nanoparticles Modified Covalent Triazine Frameworks towards Highly-Efficient Dehydrogenation of Dipentene for p-Cymene Production
by Yanni Liu, Yonghui Chen, Yikai Wang, Zijie Xiao, Yilin Chen, Jianchun Jiang, Xiaoping Rao and Yun Zheng
Catalysts 2023, 13(9), 1248; https://doi.org/10.3390/catal13091248 - 28 Aug 2023
Viewed by 875
Abstract
The generation of p-cymene from the catalytic dehydrogenation of dipentene is one of the most vital approaches for the synthesis of p-cymene in the chemical industry. Herein, CTF polymer was synthesized by an ionothermal method via using terephthalonitrile as monomer and NaCl-KCl-ZnCl2 [...] Read more.
The generation of p-cymene from the catalytic dehydrogenation of dipentene is one of the most vital approaches for the synthesis of p-cymene in the chemical industry. Herein, CTF polymer was synthesized by an ionothermal method via using terephthalonitrile as monomer and NaCl-KCl-ZnCl2 ternary mixture as catalyst and solvent, and Pd/CTF catalyst was prepared by loading CTF matrix with Pd nanoparticles via a chemical reduction method. The as-obtained Pd/CTF catalyst with the loading amount of 5 wt% Pd showed remarkable catalytic activity in the dehydrogenation of dipentene to p-cymene with a high conversion rate of 100% and a high selectivity of 96% at the reaction temperature of 220 °C in a stainless-steel autoclave containing 0.1 MPa of Ar gas, and also exhibited good stability in the recycling tests. The strong interaction between Pd nanoparticles and CTF and the enhanced electron transfer at the metal-semiconductor interface contribute to the outstanding catalytic performance of Pd/CTF for the dehydrogenation of dipentene to p-cymene. This work demonstrates that the metal-semiconductor catalysts possessed excellent potential in the production of high-value-added chemical products from terpenes conversion. Full article
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13 pages, 4230 KiB  
Article
Tailoring Morphology in Hydrothermally Synthesized CdS/ZnS Nanocomposites for Extraordinary Photocatalytic H2 Generation via Type-II Heterojunction
by Mianli Huang, Maoqing Yu, Ruiru Si, Xiaojing Zhao, Shuqin Chen, Kewei Liu and Xiaoyang Pan
Catalysts 2023, 13(7), 1123; https://doi.org/10.3390/catal13071123 - 19 Jul 2023
Cited by 3 | Viewed by 958
Abstract
CdS@ZnS core shell nanocomposites were prepared by a one-pot hydrothermal route. The morphology of the composite was tuned by simply changing the Zn2+ precursor concentration. To characterize the samples prepared, various techniques were employed, including XRD, FESEM, TEM, XPS and UV-vis DRS. [...] Read more.
CdS@ZnS core shell nanocomposites were prepared by a one-pot hydrothermal route. The morphology of the composite was tuned by simply changing the Zn2+ precursor concentration. To characterize the samples prepared, various techniques were employed, including XRD, FESEM, TEM, XPS and UV-vis DRS. The band gaps of CdS and ZnS were measured to be 2.26 and 3.32 eV, respectively. Compared with pure CdS, the CdS@ZnS samples exhibited a slight blue shift, which indicated an increased band gap of 2.29 eV. The CdS@ZnS core shell composites exhibited efficient photocatalytic performance for H2 generation under simulated sunlight illumination in contrast to pure CdS and ZnS. Additionally, an optimized H2 generation rate (14.44 mmol·h−1·g−1cat) was acquired at CdS@ZnS-2, which was approximately 4.6 times greater than that of pure CdS (3.12 mmol·h−1·g−1cat). Moreover, CdS@ZnS heterojunction also showed good photocatalytic stability. The process of charge separation over the photocatalysts was investigated using photoelectrochemical analysis. The findings indicate that the CdS@ZnS nanocomposite has efficient charge separation efficiency. The higher H2 generation activity and stability for CdS@ZnS photocatalysts can be attributed to the intimate interface in the CdS@ZnS core–shell structure, which promoted the light absorption intensity and photoinduced charge separation efficiency. It is expected that this study will offer valuable insights into the development of efficient core shell composite photocatalysts. Full article
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15 pages, 3855 KiB  
Article
Investigation on the Edge Doping Process of Nitrogen-Doped Carbon Materials by In Situ Pyrolysis Mass Spectrometry and Laser-Induced Acoustic Desorption Mass Spectrometry
by Yihuang Jiang, Zaifa Shi, Qingjie Zeng, Jiangle Zhang, Zefeng Deng, Qiaolin Wang, Jing Yang, Jingxiong Yu, Zhengbo Qin and Zichao Tang
Catalysts 2023, 13(5), 830; https://doi.org/10.3390/catal13050830 - 30 Apr 2023
Cited by 1 | Viewed by 1476
Abstract
Nitrogen-doped carbon materials demonstrate high performance as electrodes in fuel cells and higher oxygen reduction reactivity than traditional Pt-based electrodes. However, the formation process of nitrogen-doped carbon materials has long been a mystery. In this study, the formation mechanism of nitrogen-doped carbon materials [...] Read more.
Nitrogen-doped carbon materials demonstrate high performance as electrodes in fuel cells and higher oxygen reduction reactivity than traditional Pt-based electrodes. However, the formation process of nitrogen-doped carbon materials has long been a mystery. In this study, the formation mechanism of nitrogen-doped carbon materials from polyaniline (PANI) pyrolysis was studied by the combination of in situ pyrolysis vacuum ultraviolet photoionization time-of-flight mass spectrometry (Py-VUVPI-TOF MS) and substrate-enhanced, laser-induced acoustic desorption source time-of-flight mass spectrometry (SE-LIAD-TOF MS). The initial pyrolysis species, including free radicals and intermediates, were investigated via in situ Py-VUVPI-TOF MS during the temperature-programmed desorption process (within tens of microseconds). The pyrolysis residues were collected and further investigated via SE-LIAD-TOF MS, revealing the product information of the initial pyrolysis products. The results show that the edge doping of carbon materials depends on free radical reactions rather than the direct substitution of carbon atoms by nitrogen atoms. Meanwhile, pyrrole nitrogen and pyridine nitrogen are formed by the free radical cyclization reaction and the amino aromatization reaction at the initial stage of pyrolysis, while the formation of graphitic nitrogen depends on the further polymerization reaction of pyrrole nitrogen and pyridine nitrogen. Full article
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12 pages, 2245 KiB  
Article
Coal as an Effective Catalyst for Selective Oxidative Dehydrogenation of Propane to Propene
by Qiuwen Liu, Yuhua Zhang, Yawei Wu, Mingxia Song and Caijin Huang
Catalysts 2023, 13(3), 628; https://doi.org/10.3390/catal13030628 - 21 Mar 2023
Viewed by 1191
Abstract
Coal is a readily available and inexpensive material. However, its direct use as a catalyst is still rare, but attractive for practical application. In this paper, coal was directly used as a catalyst for the selective oxidative dehydrogenation of propane to propene. It [...] Read more.
Coal is a readily available and inexpensive material. However, its direct use as a catalyst is still rare, but attractive for practical application. In this paper, coal was directly used as a catalyst for the selective oxidative dehydrogenation of propane to propene. It exhibited a high selectivity over 90% with a yield of 8.4% at a high space velocity (12,000 mL·(h·g-cat)−1). The productivity up to 2.84 gC3H6 gcat−1 h−1 was obtained with propene selectivity above 80% (20,000 mL·(h·g-cat)−1). The kinetic showed first-order dependence with respect to propane or oxygen partial pressures. Meanwhile, electron paramagnetic resonance (EPR) and X-ray photoelectron spectrum (XPS) demonstrated that the carbonyl groups act as active sites for oxidative dehydrogenation of propane to propene. This work expands the use of earth-abundant and low-price coal in catalysis with expectable scale application. Full article
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12 pages, 9494 KiB  
Article
Coupling the Piezoelectric Effect and the Plasmonic Effect to Enhance the Photocatalytic Degradation of Ciprofloxacin in Au-Ferroelectric Bi4Ti3O12 Nanofibers
by Chao Meng, Junfeng Peng, Lei Wang, Hao Han, Kai Yang and Daotong You
Catalysts 2023, 13(3), 621; https://doi.org/10.3390/catal13030621 - 20 Mar 2023
Cited by 1 | Viewed by 1224
Abstract
In this study, ferroelectric Bi4Ti3O12 and Au-Bi4Ti3O12 nanofibers were synthesized by electrospinning and ion sputtering. The piezoelectric effect of Bi4Ti3O12 and the surface plasmon effect of Au were [...] Read more.
In this study, ferroelectric Bi4Ti3O12 and Au-Bi4Ti3O12 nanofibers were synthesized by electrospinning and ion sputtering. The piezoelectric effect of Bi4Ti3O12 and the surface plasmon effect of Au were used to improve the photogenerated electron–hole separation and optical absorption. The results of the characterization showed successful preparation of the orthorhombic Bi4Ti3O12 nanofibers, in which the absorption band edge was 426 nm with a 2.91 eV band gap. The piezo-photocatalytic activity of the Bi4Ti3O12 was tested through the degradation of the antibiotic ciprofloxacin under three different experimental conditions: light, vibration, and light plus vibration. All of the ciprofloxacin was degraded after 80 min in piezo-photocatalytic conditions, with a piezo-photocatalytic degradation rate of 0.03141 min−1, which is 1.56 and 3.88 times, respectively, that of photocatalysis and piezo-catalysis. After loading Au on the Bi4Ti3O12, the degradation efficiency was improved under all three conditions, and the piezoelectric photocatalytic efficiency of Au-Bi4Ti3O12 for ciprofloxacin degradation was able to reach 100% in 60 min with a piezo-photocatalytic degradation rate of 0.06157 min−1. The results of the photocurrent and impedance tests indicated that the photocurrent density of Bi4Ti3O12 nanofibers loaded with Au is increased from 5.08 × 10−7 A/cm2 to 8.17 × 10−6 A/cm2, which is 16.08 times higher than without loading the Au. This work provides an effective way to improve the conversion efficiency of photocatalysis to degrade organic pollutants by combining the plasmon effect and the piezoelectric effect. Full article
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