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A generic strategy for preparation of TiO2/BixMyOz (M?=?W, Mo) heterojunctions with enhanced photocatalytic activities
摘要： Employment of nanoscale TiO2/BixMyOz (M = W, Mo) heterojunctions is one of the most promising strategies for improving the photocatalytic efficiency. However, the controllable synthesis and morphology modification of these heterojunctions are still highly challenging. In this work, we developed a generic approach to hydrothermally synthesize TiO2/BixMyOz heterojunctions and tailor their morphologies. The key of this strategy is to intentionally utilize the surface defects of TiO2 as highly active sites to adsorb the intermediate hydrolysis-products, which is in marked contrast to the conventionally direct precipitation methods. In the subsequent hydrothermal reactions, MO4 2- replaced the hydroxyl and nitrate radicals to form stable TiO2/BixMyOz heterojunctions, in which the second phase BixMyOz occupied the defect sites of TiO2 nanobelts. Under visible light irradiation, the photocatalytic reaction rate constant of TiO2/Bi2WO6 heterojunctions was four times higher than that of single phase Bi2WO6 nanosheets, while the photocatalytic reaction rate constant of TiO2/Bi3.64Mo0.36O6.55 heterojunctions exhibited a seven-fold increase compared with Bi3.64Mo0.36O6.55 nanopaticles. The substantial enhancement of photocatalytic activity is primarily ascribed to the matching energy band structure in the TiO2/BixMyOz heterojunctions, which is able to improve the separation efficiency of photo-generated electron-hole pairs and prolong the lifetime of charge carriers in the heterojunctions.
关键词： TiO2/Bi2MoO6 heterojunctions,photocatalytic activities,TiO2/Bi2WO6 heterojunctions,defects induction,TiO2/Bi3.64Mo0.36O6.55 heterojunctions
更新于2025-09-23 15:23:52
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Enhanced photocatalytic activity of hydrogenated BiVO4 with rich surface-oxygen-vacancies for remarkable degradation of tetracycline hydrochloride
摘要： In this work, for the first time the hydrogenation treatment was employed to introduce oxygen vacancies on the surface of BiVO4 (BVO) particles, and the influence of hydrogenation on the morphological structure and photocatalytic activity of BVO was explored. Compared to the pristine BVO, a disordered amorphous layer was observed on the surface of the hydrogenated BVO (HBVO) sample. The disordered layer was due to the formation of surface oxygen vacancies in HBVO, as verified by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectra. Meanwhile, the band gap of HBVO was slightly narrowed accompanying with a higher optical absorption ability. The photocatalytic measurements demonstrated that under 30 min visible light (λ ≥ 420 nm) illumination the HBVO sample could photocatalytically degrade 98% of tetracycline hydrochloride (TCH), which was much higher than the pristine BVO (~52%), and the calculated pseudo-first-order degradation rate constant (k) of HBVO (~0.118 min?1) was about 5 times that of BVO, confirming that the hydrogenation treatment could significantly improve the photocatalytic activity of BVO. In addition, the photocatalytic mechanism of HBVO for enhanced photocatalytic TCH removal was also discussed. The present work demonstrates the feasibility of employing the hydrogenation treatment to develop highly efficient visible light BVO-based photocatalysts for photocatalytic removal of antibiotics, and also deepens the understanding of the correlation between surface oxygen vacancies and photocatalytic performance of semiconductor photocatalysts.
关键词： BiVO4,Photocatalytic activities,Tetracycline hydrochloride removal,Hydrogenation,Surface oxygen vacancies
更新于2025-09-23 15:23:52
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Degradation of benzothiophene in diesel oil by LaZnAl layered double hydroxide: photocatalytic performance and mechanism
摘要： A new type of photocatalytic La3+–Zn2+–Al3+–MoO4 2- layered double hydroxide (LDH) material (molar ratio, La/Zn/Al = 1:7:2) was prepared by a complexing agent-assisted homogeneous precipitation technique. The structure of the prepared LDH material was systematically studied. Under UV irradiation, the desulfurization efficiency of the LDH material was 87% in 2 h. For La3+–Zn2+–Al3+–MoO4 2- LDH material, the introduction of MoO4 2- increased the interlayer space for promoting the adsorption of benzothiophene (BT), and MoO4 2- might provide active sites for the oxidation of BT, resulting in the high desulfurization efficiency.
关键词： Photocatalytic activities,Catalytic oxidation mechanism,LDH,Homogeneous precipitation
更新于2025-09-23 15:23:52
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Synthesis and characterization of CdS@ZnO nanoribbon@quantum dot and their enhanced visible-light-driven photocatalytic activities
摘要： CdS/ZnO nanoribbon/quantum dot was prepared using thermal decomposition method. Size and distribution of ZnO quantum dots on CdS nanobelt were controlled by concentrations of zinc acetate ethanol solution and thermal decomposition temperature. The structure and optical properties of CdS nanobelts and CdS/ZnO heterostructures are studied by XRD, TEM, PL and Raman scattering and UV–Vis absorption spectra. The photocatalytic performances of CdS nanobelts and CdS/ZnO heterostructures are tested by photocatalytic degradation of RhB aqueous solution under visible light irradiation. Compared with that (83.57%) of CdS nanobelts, the degradation rate (88.66%) of RhB using CdS/ZnO heterostructures as catalyst is significantly improved, which suggests better development prospect in photocatalytic technology and photoelectric device.
关键词： photocatalytic activities,thermal decomposition method,CdS@ZnO nanoribbon@quantum dots,optical properties
更新于2025-09-23 15:19:57
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Surfactant assisted sonochemical synthesis of zinc tungstate nanoparticles: Anode for Li-ion battery and photocatalytic activities
摘要： Herein, we report a simple, economic and low-cost surfactant assisted sonochemical synthesis of ZnWO4 nanoparticles. The structural and morphological features of nanoparticles were characterized by X-ray di?raction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, photoluminescence (PL) spectroscopy and transmission electron microscopy. ZnWO4 had been proven to be one of the most promising electrodes for energy storage and found that the discharge capacity was of 173 mA h g?1 even after 20 cycles at 0.1C rate. In addition to this, good photocatalytic degradation e?ciency (98.6% in 120 minutes) was also achieved through Rhodamine B as a model of pollutant system.
关键词： photocatalytic activities,Rhodamine B,sonochemical synthesis,Li-ion battery,ZnWO4 nanoparticles
更新于2025-09-23 15:19:57
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Controlled growth of Cu <sub/>2a??x</sub> S sheet-like nanoshells and Cu <sub/>2a??x</sub> Sa??CdS pa??n junctions on Au nanorods with coupled plasmon resonances and enhanced photocatalytic activities
摘要： In this study, we propose an approach to grow Cu2?xS sheet-like nanoshells on Au nanorods with the aid of Ag2S auxiliary templates. The Ag2S semi-shells are first grown on the side-surface of the Au nanorods and then, the Cu2?xS sheet-like nanoshells are selectively grown on the opposite side, which is beneficial for improving the controllability of the growth sites of the Cu2?xS sheet-like nanoshells. The Cu2?xS–CdS p–n junctions grown on Au nanorods are produced by replacing Ag+ with Cd2+ in the as-prepared Au/(Cu2?xS–Ag2S), so that Au/(Cu2?xS–CdS) heterorods with non-central symmetric shells of Cu2?xS–CdS p–n junctions are formed. By carefully adjusting the effective thickness of the Cu2?xS–CdS junctions, the optimized photocatalytic activity of the Au/(Cu2?xS–CdS) heterorods is obtained, and it is about 1.62 and 1.22-fold that of Au/Cu2?xS and Au/CdS, respectively. The improved photocatalytic performance of the Au/(Cu2?xS–CdS) heterorods is attributed to the effective charge carriers at the interfaces of CdS–Au, Cu2?xS–Au and the Cu2?xS–CdS p–n junction. Our findings provide a strategy for the optimal design of plasmon–exciton heterostructures with improved photocatalytic activity.
关键词： Cu2?xS,Ag2S auxiliary templates,plasmon resonances,photocatalytic activities,Au nanorods
更新于2025-09-19 17:13:59
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The synthesis of Bi2S3/2D-Bi2WO6 composite materials with enhanced photocatalytic activities
摘要： Bi2S3/2D-Bi2WO6 composite materials which combined 2D-Bi2WO6 with Bi2S3 nanoparticles were prepared via ion exchange method. The mass ratio of Bi2S3 nanoparticle could be modulated by changing the quantity of thioacetamide (TAA). For Bi2S3/2D-Bi2WO6 composite materials, Bi2S3 nanoparticles dispersed on the surface of Bi2WO6 nanosheets. The photocatalytic activity was evaluated by photodegradation rhodamine B (RhB) under visible light. RhB was photodegraded nearly completely by BWS-2, while only 67% was photodegraded by Bi2WO6 nanosheet after 5 hours’ visible light irradiation. Based on the optical and electrochemical measurements, Bi2S3/2D-Bi2WO6 composite materials have prolonged carriers’ lifetime, improved carriers’ separation efficiency and decreased carriers’ recombination efficiency. These results endow Bi2S3/2D-Bi2WO6 composite materials with high photocatalytic activities.
关键词： Bi2S3/2D-Bi2WO6,ion exchange method,photocatalytic activities,visible light,composite materials
更新于2025-09-10 09:29:36
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Architecture of Biperovskite-Based LaCrO <sub/>3</sub> /PbTiO <sub/>3</sub> p–n Heterojunction with a Strong Interface for Enhanced Charge Anti-recombination Process and Visible Light-Induced Photocatalytic Reactions
摘要： Erection of a resourceful p?n heterojunction is a state-of-the-art tactic to flourish the charge anti-recombination process at the heterojunction interface and boost the photocatalytic activities under visible light irradiation. In the present work, we have engineered a new series of PbTiO3/LaCrO3 (PT/LC) p?n heterojunction through a facile two-step combustion process. The structural, interface, and optical analysis distinctly revealed a strong intact between p-type LaCrO3 and n-type PbTiO3, elucidating their electronic channelization and substantial reduction of electron?hole recombination at the PbTiO3/LaCrO3 interface, which extend the lifetime and population of photogenerated charges in the p?n heterojunction material. The asymmetry photocurrent in the opposite directions and an inverted characteristic V-shape Mott?Schottky plot of the optimal PT/LC (7/3) material demonstrated the construction of a p?n heterojunction. The optimal p?n heterojunction possesses excellent photo-stability, and it revealed the highest photocatalytic activity toward degradation of phenol, that is, 86% and hydrogen generation, that is, 343.57 μmol in 2 h. The enhanced photocatalytic activities of the p?n heterojunction materials in comparison to pristine ones are due to the higher separation charge carriers across the p?n heterojunction interface, which was deeply elucidated by carrying out electrochemical impedance spectroscopy, time-resolved photoluminescence spectroscopy, and photoluminescence analyses. These materials pave a new way to design the interface intact photocatalyst with an ultrafast approach for migration of photoexcited electrons across the p?n heterojunction and enhance the photocatalytic activities.
关键词： p?n heterojunction,PbTiO3/LaCrO3,visible light irradiation,photocatalytic activities,charge anti-recombination
更新于2025-09-10 09:29:36