- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
One pot synthesis of bismuth oxide/graphitic carbon nitride composites with high photocatalytic activity
摘要： A one pot synthesis of heterostructured bismuth oxide (Bi2O3)/graphitic carbon nitride (g-CN) photocatalysts was developed using Bi(NO3)3 and melamine in 1 M HNO3 as precursors. SEM, TEM and XPS analyses demonstrate that Bi2O3 is closely associated to g-CN, producing contacted interfaces between the two materials. The loading in Bi2O3 was varied from 1.25 to 10 wt% and the highest photocatalytic activity was obtained for the composite containing 2.5% BBN. The Bi2O3 (2.5%)/g-CN material exhibits excellent photocatalytic activity under visible light irradiation for the degradation of RhB as well as a good stability and reusability. Reactive species trapping experiments demonstrated that superoxide O2? radicals and to a lesser extent holes play a key role in the decomposition of the dye. The high photocatalytic activity of the Bi2O3 (2.5%)/g-CN composite originates from the effective separation of photogenerated charge carriers, which was confirmed by photoluminescence and photocurrent measurements, and from its high specific surface area (26.1 m2/g). The convenient and low cost method developed for the preparation of g-CN-based photocatalysts is of high interest for the synthesis of new heterostructured materials for environmental remediation.
关键词： Graphitic carbon nitride,Heterostructured photocatalyst,Bismuth oxide
更新于2025-09-04 15:30:14
-
Facile photodeposition synthesis of novel Ag/4-Br/Bi2O3 composite photocatalyst
摘要： A novel Ag/4-Br/Bi2O3 composite photocatalyst was prepared by the hydrothermal and photodeposition method, and characterized by XRD, SEM, TEM and UV–vis analysis, respectively. The results indicated that the nanoparticles of Ag were successfully deposited on the surface of 4-Br/Bi2O3 composite. The as-prepared sample of Ag/4-Br/Bi2O3 showed higher photocatalytic activity than that of pure Bi2O3 or 4-Br/Bi2O3 through photodegradation of methyl orange(MO) under visible light. The enhanced photocatalytic activity could be attributed to the expansion of photoresponse range and the acceleration of carriers transmit caused by loading of Ag nanoparticles. Additionally, a possible photocatalytic mechanism of the Ag/4-Br/Bi2O3 composite was put forward.
关键词： Semiconductors,Ag/4-Br/Bi2O3,Photocatalyst,Composite materials
更新于2025-09-04 15:30:14
-
Effect of substituting molybdenum atoms with tungsten on photocatalyst activity of cesium salt of keggin type polyoxometalates decorated magnetic ceria
摘要： Herein the potential use of cesium salts of polyoxometalate incorporated ceria and magnetic ceria as a photocatalyst for the photodegradation of Congo red was studied. Polyoxometalates salts (cesium salts of tungestophosphoric acid (H3PW12O40), molybdophosphoric acid (H3PMo12O40), and 6-molybdo tungestophosphoric acid (H3PW6Mo6O40)), having Keggin structure with large cations like Cs+, are porous materials. The morphological and structural studies of synthesized nanocomposites were carried out using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Results indicated that the Fe3O4@CeO2/Cs-PMoyW12-yO40 and CeO2/Cs-PMoyW12-yO40 (y=0, 6, 12) nanocomposites are successfully synthesized. UV-vis diffuse reflectance spectroscopy determined the absorption edge and band gap energies of the prepared nanocomposites as a direct semiconductor. All the obtained structures were applied as photocatalys for degradation of Congo red dye in aqueous solutions under visible light. The Fe3O4@CeO2/Cs-PMo6W6O40 photocatalyst exhibited the highest photocatalytic activity under visible light.
关键词： Photocatalyst,Ceria,Polyoxometalate,Congo red,Nanocomposite,Magnetic
更新于2025-09-04 15:30:14
-
Magnetically Recyclable MoS <sub/>2</sub> /Fe <sub/>3</sub> O <sub/>4</sub> Hybrid Composite as Visible Light Responsive Photocatalyst with Enhanced Photocatalytic Performance
摘要： Photocatalysis is one of the most promising technologies in wastewater treatment. However, the inactivity to visible light and the inconvenience to recycle severely limit its practical application. In this work, via a facile hydrothermal method, Fe3O4 NPs were integrated onto the surfaces of 3D ball-flower-like MoS2 microspheres as efficiently visible light responsive and magnetically recyclable photocatalysts. Experimental results indicate that, an optimal loading amount (20 wt.%) of Fe3O4 NPs can not only effectively enhance the photocatalytic ability of the MoS2/Fe3O4 (MF) hybrid composite with approximately 2 times better than pure MoS2, but also make it conveniently recycle from water by an external magnetic field. The photoelectrochemical studies also reveal that the incorporation of Fe3O4 NPs can effectively enhance the charge transfer rate and accelerate separation of photo-induced charge carriers. The surface catalytic mechanism of MF hybrid composite was also explored through XPS spectra. With both the excellent photocatalytic performance and magnetical recyclability, the 20wt%-MF hybrid composite is considered to be a promising and competitive photocatalyst for wastewater treatment utilizing solar energy.
关键词： magnetical recyclability,Fe3O4 NPs,MoS2,photocatalyst,visible light responsive
更新于2025-09-04 15:30:14
-
Visible light thiocyanation of <i>N</i> -bearing aromatic and heteroaromatic compounds using Ag/TiO <sub/>2</sub> nanotube photocatalyst
摘要： In this study, Ag/TiO2 nanotubes (Ag/TNT) were synthesized via simple hydrothermal process, and this photocatalyst was successfully exploited in thiocyanation reactions at room temperature under visible light irradiation. Four classes of important heterocyclic compounds including indole, aniline, pyrrole and 2-amino thiazole derivatives via Ag/TNT treated with ammonium thiocyanate formed the corresponding thiocyano compounds in moderate to excellent yields. Plasmonic property and catalytic performance of Ag nanoparticles (which mainly deposited on the surface of TNT) in absorbing species containing sulfur atoms were key components for the reactions to proceed. This potent, simple and versatile protocol reported for the first time afforded thiocyanation reactions of aniline, pyrrole and 2-amino thiazole derivatives under visible light. The reactions proceeded through a radical pathway by applying air molecular oxygen as a low-cost and environmentally friendly terminal oxidant.
关键词： thiocyanation,photocatalyst,visible light,heterocyclic compounds,Ag/TiO2 nanotubes
更新于2025-09-04 15:30:14
-
Green synthesis of g-C <sub/>3</sub> N <sub/>4</sub> -Pt catalyst and application to photocatalytic hydrogen evolution from water splitting
摘要： The g-C3N4-Pt photocatalyst was successfully prepared by the combination of a biosynthesis method and sol deposition, which were used for hydrogen evolution from water splitting. The layers of g-C3N4 are thinned and the Pt nanoparticles simultaneously become tightly bound to g-C3N4 by secondary calcination in the process of synthesizing the g-C3N4-Pt photocatalyst. Analysis of the morphological structure and instrumental characterization of the optical performance revealed that the Pt nanoparticles were successfully loaded and well dispersed on the surface of g-C3N4. Furthermore, the absorption wavelength range of the g-C3N4-Pt photocatalyst in visible light was widened and the absorption increased. The activity and photostability of the g-C3N4-Pt photocatalyst for hydrogen evolution under visible light irradiation (λ≥420 nm) were excellent. The rate of H2 evolution reached 582.4 mmol h?1 g?1, and the quantum efficiency (QE) reached 2.70% at 420 nm.
关键词： green synthesis,hydrogen evolution,visible-light photocatalysis,G-C3N4-Pt photocatalyst
更新于2025-09-04 15:30:14
-
Facial synthesis of a novel Ag <sub/>4</sub> V <sub/>2</sub> O <sub/>7</sub> /g‐C <sub/>3</sub> N <sub/>4</sub> heterostructure with highly efficient photoactivity
摘要： A novel Ag4V2O7/g-C3N4 heterostructure was synthesized by a facial etching method in ammonia solution using Ag2VO2PO4/g-C3N4 as a self-sacrifice precursor. With the concentration of ammonia solution increasing from 0.05 to 0.2 M, phase transformation took place, described as: Ag2VO2PO4/g-C3N4 → Ag2VO2PO4/Ag4V2O7/g-C3N4 → Ag4V2O7/g-C3N4. Compared with pristine Ag2VO2PO4/g-C3N4, the etched samples of Ag4V2O7/g-C3N4 and Ag2VO2PO4/Ag4V2O7/g-C3N4 exhibited dramatically improved activity for the degradation of methylene blue (MB), methyl orange (MO) and imidacloprid under visible light irradiation. When etched with 0.15 M ammonia solution, an Ag4V2O7/g-C3N4 heterostructure was obtained that exhibited the highest photoactivity. This photocatalyst was nearly 9.1, 3.0, and 24.3 times more efficient than pristine Ag2VO2PO4/g-C3N4 for degradation of MB, MO and imidacloprid, respectively. The excellent photocatalytic performance can be ascribed to the as-obtained well-defined Ag4V2O7/g-C3N4 heterojunction, which improves the separation and transfer efficiency and prolongs the lifetime of photoinduced charges. In addition, the stability and dominant radicals were investigated.
关键词： photocatalyst,heterostructure,Ag4V2O7/g-C3N4,visible light
更新于2025-09-04 15:30:14
-
Effect of Tin and Strontium Doping on the Photocatalytic Activity of Zinc Sulphide Nanoparticles for the Photocatalytic Degradation of Resorcinol under Solar and Ultra-Violet Light
摘要： Tin (Sn) and Strontium (Sr) doped Zinc Sulphide and pure Zinc Sulphide photocatalyst have been prepared by Sol-Gel method. The prepared photocatalyst have been characterised by Thermo gravimetric Differential Thermal Analysis, Scanning Electron Microscopy, Energy Dispersive X-ray, X-Ray Diffraction, ultra-violet visible spectroscopy and photoluminescence spectroscopy. Characterization Techniques have provided information of wurtzite hexagonal structure of Zinc Sulphide. The PL spectra have shown the blue shift of Zinc Sulphide after doping it with Tin and Strontium. Photocatalytic degradation study was done by the complete degradation of an organic pollutant Resorcinol in Sun light as well as in UV-light. The factors affecting the photocatalytic activity of photocatalyst viz. pH, catalyst loading and reuse of photocatalyst have been studied along with the photocatalytic degradation of Resorcinol. These external parameters have considerable influenced on the phtocatalytic activity of Zinc Sulphide.
关键词： Photocatalyst,Pollution,Sol-gel synthesis,Doping,Zinc sulphide nanoparticles,Photoluminescence
更新于2025-09-04 15:30:14
-
Effect of Zn Content on the physicochemical Characteristics and Photoactivity of ZnO supported Activated Carbon
摘要： In the present work, synthesis of ZnO dispersed onto activated carbon (ZnO/AC) is reported. Synthesis was conducted by using impregnation method by zinc acetate as precursor at varied Zn content. A systematic characterization of ZnO/C materials was performed using XRD, SEM, gas sorption analyzer and diffuse reflectance UV-Visible spectrophotometer. Photoactivity of the materials was studied in phenol removal via photooxidation mechanism. From the study it is confirmed that ZnO dispersion give acceleration of phenol removal refer to surface area contribution. It is no linear correlation of each physical character to the photocatalytic activity.
关键词： ZnO,Activated Carbon,Photocatalyst,Photooxidation
更新于2025-09-04 15:30:14