- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Development of Graphene Based Photocatalysts for CO2 Reduction to C1 Chemicals: A brief Overview
摘要： Transformation of CO2, a notorious greenhouse gas, to solar fuels is a promising strategy to alleviate the issues of global warming, environmental pollution, and climatic changes. Additionally, the CO2 conversion to useful chemicals/ fuels also possess a great potential to well match the energy demand in a sustainable manner. Hence, such exceptional benefits of harnessing CO2, by capitalizing sunlight, to valuable chemicals/fuels through photocatalysis, as one of the effective approach in the respective domain, have triggered great interest among researchers and scientific community. In this regard, utilization of customary and standard photocatalytic materials, specifically metal oxides like TiO2, are modified to provide enhanced performance, which is usually restricted due to limited intrinsic optical and physicochemical properties. To overcome such a critical issue of limited performance, several strategies like metals and non-metals doping, hetero-junctions, composites and nanostructures formation of photocatalytic materials have been investigated. Recently, with the invention of graphene and its derivatives, graphene based photocatalytic materials have been a topic of great interest, specifically for photocatalysts development and photocatalysis application. Graphene and its derivatives, due to their extraordinary physiochemical and electrical properties like high surface area, stability, anticorrosion capacity, photosensitizer, and excellent conductivity, can knock out the performance limiting constraints faced by traditional photocatalysts. Thus, Graphene based photocatalysts can be a feasible strategy to break new grounds in the field of photocatalytic CO2 reduction (PCCR) to useful chemicals/ fuels, i.e. conversion of sunlight to fuels. Herein, a summarized overview is presented for the latest development in graphene-based photocatalysts, focusing various strategies and researches being investigated in relation to the, utility of graphene and its derivatives for solar fuels generation, particularly C1 chemicals like CO, CH4, CH3OH, and insights to their role in improving efficacy of photocatalysts.
关键词： Photocatalytic activity,Photocatalytic CO2 reduction,Solar fuels,Product Selectivity,Graphene based photocatalysts
更新于2025-09-09 09:28:46
-
Enhancing saturation magnetization of Mg ferrite nanoparticles for better magnetic recoverable photocatalyst
摘要： Simple combustion route was implemented for the preparation of Mo-substituted magnesium ferrite nanoparticles; MgFe2?2xMoxO4 (x = 0.0, 0.1, 0.2 and 0.3). Samples, with x = 0.0, 0.1 and 0.2, revealed only the cubic spinel ferrite phase. Sample with x = 0.3 showed very small amount of FeMoO4, beside MgFe2O4. The lattice parameter diminished with increasing molybdenum contents to x = 0.1, then increased at x ≥ 0.2. The saturation magnetization (Ms) increased from 15.65 to 32.05 emu/g with low level of Mo6+ substitution (x = 0.1), then declined with x > 0.1. This is the first investigation to report Ms of Mg ferrite nanoparticles higher than its bulk value. The change in magnetic properties is correlated with cation distribution between tetrahedral sites (A) and octahedral sites (B). Mo6+ replaced the Fe3+ position in the tetrahedral A-sites for x = 0.1. In samples with x ≥ 0.2, Mo6+ occupied both A-sites and B-sites. Mo substitution decreased the crystallite size and increased the microstrain. Mo substitution in MgFe2O4 enhanced the photocatalytic action compared to bare MgFe2O4. The enhancement was due to the increase in structure defect that inhibits the electrons–holes recombination as well as the increase in surface area.
关键词： photocatalytic activity,Mg ferrite nanoparticles,Mo substitution,saturation magnetization
更新于2025-09-09 09:28:46
-
An efficient fabrication of ZnO–carbon nanocomposites with enhanced photocatalytic activity and superior photostability
摘要： Synthesis of carbon nanoparticles (CNPs) and their composite with ZnO has proposed for the first time by combustion of camphor and chemical precipitation method. TEM image shows the surface of ZnO covered by tiny CNPs and acts as structure directing agent that transforms ZnO nanorods to uniform spherical ZnO. CNPs play a vital role to improve the photocatalytic activity and photostability of ZnO up to five runs due to impeding the photo-corrosion of ZnO. Enhance in the photocatalytic activity of ZnO–carbon nanocomposite could be attributed to the excellent dye adsorption capacity, direct photooxidation of dye and suppression of photoinduced electron–hole recombination. The presence of CNPs in nanocomposite served as the main role in accepting the photogenerated electrons due to electronic interaction between ZnO and CNPs. The cytotoxicity studies of meristematic root tip cells of Allium cepa reveals that photocatalytically degraded products were less toxic.
关键词： Photostability,ZnO–carbon nanocomposites,Photocatalytic activity,Chemical precipitation method,Camphor combustion
更新于2025-09-09 09:28:46
-
One-step introduction of metallic Bi and non-metallic C in Bi2WO6 with enhanced photocatalytic activity
摘要： One-step introduction of metallic Bi, non-metallic C into Bi2WO6 was successfully prepared via a facile hydrothermal synthetic route. The obtained materials were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy (XPS), nitrogen absorption–desorption isotherms, photoluminescence spectroscopy, photocurrent responses, electrochemical impedance spectroscopy (EIS), electron paramagnetic resonance (EPR), UV–vis diffuse reflectance spectra (DRS). As a result, C/Bi codecorated Bi2WO6 shows profoundly photocatalytic activity in comparison with undoped Bi2WO6 for decomposition of various industrial pollutants, including phenol, ciprofloxacin, bisphenol A, rhodamine B, and methyl orange under visible light (λ ≥ 420 nm). The enhanced photocatalytic properties may be ascribed to the fact that the synergistic effects of the SPR effect of Bi metal and the hybrid orbital constructed by C doping not only enhance the absorption of visible light but also accelerate the separation and migration of photo-generated carriers. Moreover, on the basis of the radical species trapping experiments, EPR analyses, DRS technique and Mott–Schottky plots, we proposed a simple photocatalytic mechanism.
关键词： Non-metallic C,Bi2WO6,Hydrothermal synthesis,Metallic Bi,Photocatalytic activity
更新于2025-09-09 09:28:46
-
Microwave-assisted preparation and enhanced photocatalytic activity of Bi2WO6/BiOI heterojunction for organic pollutants degradation under visible-light irradiation
摘要： In this research, we adopted morphology control and constructing p-n heterojunction to boost the photocatalytic performance of BiOI. BiOI with three morphologies (nanoplate, micro-flower, microsphere) was fabricated via a wet-chemical method at room temperature using different solvents. And Bi2WO6/BiOI microspheres were successfully prepared by a microwave-assisted synthetic method. The as-synthesized samples were characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and High-resolution Transmission Electron Microscopy (HRTEM). The results of photo-degradation experiment demonstrated that BiOI-3 and BWOI-3 show high photocatalytic performance towards methyl orange (MO) and bisphenol A (BPA) degradation due to the high specific surface area, synergistic effect between p-type BiOI and n-type Bi2WO6 and high separation efficiency of electron-hole pairs, which is verified by Brunauer-Emmett-Teller (BET), Photocurrent (PC) and Electrochemical Impedance Spectroscopy (EIS) analysis. Moreover, the repeated photocatalytic experiment was carried out by using MO as the representative organic pollutant, manifesting the good durability of the sample.
关键词： Microwave-assisted,Heterojunction,Bi2WO6,Photocatalytic activity,BiOI
更新于2025-09-09 09:28:46
-
Band structure engineering design of g-C3N4/ZnS/SnS2 ternary heterojunction visible-light photocatalyst with ZnS as electron transport buffer material
摘要： Semiconductor heterojunction represents a family of promising photocatalysts for visible-light photocatalysis. In this work, a novel ternary g-C3N4/ZnS/SnS2 heterostructure has been designed and synthesized by a facile one-step hydrothermal method. The obtained ternary g-C3N4/ZnS/SnS2 heterostructures exhibited high photocatalytic activity in photodegradation of organic pollutants and photocurrent response irradiated by 410 nm LED light. The results demonstrated that the formation of the heterostructures can much improve the excellent photocatalytic activity if the lattice and energy level matching among the three semiconductors be satisfied, which causes efficient separation of photoinduced carriers, resulting in the high photodegradation of methylene blue (MB). As a result, the highest apparent rate constant Kapp of g-C3N4/ZnS/SnS2 hybrid is 0.148 min?1, which is 8.74, 3.22 and 37.01 times as high as that of pristine g-C3N4, SnS2 and ZnS, respectively.
关键词： ZnS,SnS2,C3N4,Buffer layer,Photocatalytic activity,Photocatalysis
更新于2025-09-09 09:28:46
-
Gallium Oxide || Synthesis, optical characterization, and environmental applications of β-Ga2O3 nanowires
摘要： In this chapter, we present the synthesis, optical characterization, and environmental applications of the β-Ga2O3 nanowires. The gap-state and near-band-edge transitions of β-Ga2O3 nanowires were identified and studied. The defects states play an important role in their optical emission and photocatalytic property. Owing to its various interesting properties such as wide bandgap, chemical and thermal stability, robust defect states, large surface to volume ratios, β-Ga2O3 nanowires are very promising in potential applications in optoelectronic, environmental applications, and fundamental research in the future.
关键词： wide-band-gap semiconductors,synthesis,optical characterization,photocatalytic activity,β-Ga2O3 nanowires,environmental applications
更新于2025-09-09 09:28:46
-
Photocatalytic Activity and Humidity Sensor Studies of Magnetically Reusable FeWO <sub/>4</sub> –WO <sub/>3</sub> Composite Nanoparticles
摘要： Different mole ratios of (8:2, 6:4, 4:6 and 2:8) iron tungstate–tungsten trioxide (FeWO4–WO3) composite nanoparticles were synthesized by solid state method. The synthesized composite nanoparticles were characterized by powder X-ray diffraction analysis (XRD), field-emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) studies. The crystalline nature and particle size of the samples were characterized by powder X-ray diffraction analysis (XRD). The morphology was confirmed by field-emission scanning electron microscopy (FE-SEM) analysis and transmission electron microscope (TEM). The energy dispersive X-ray spectroscopy (EDX) proved the purity of nanocomposites. Vibrating sample magnetometer reveals that the sample shows paramagnetic property based on the metal present in the prepared nanocomposites at room temperature. The magnetic property is due to the structural defects rather than the impurity phase. Magnetization saturation value (Ms = 398.7 emu/g) of FWWO-46 composite nanoparticles is high enough to be magnetically removed by applying a magnetic field. The composites were subjected to DC conductance measurement as a function of relative humidity in the range of 5–98%, achieved by different water vapour buffers thermostated at room temperature. The sensitivity factor, Sf = R5%/R98%, where R5% and R98% the values of the resistances measured at different RH respectively, are evaluated in Table I. If the composite has the greater value of Sf, then those materials possess the greater sensitivity towards moisture. The sensitivity factor (Sf) of the prepared composite nanoparticles was FWWO-10 (473), FWWO-82 (209), FWWO-64 (323), FWWO-46 (3956), FWWO-28 (361) and FWWO-01 (373). From this experimental value FWWO-46 exhibit the maximum Sf value of 3956 among the composites. This was due to the presence of more pores and cavities in the morphology of FWWO-46 then the other composite nanoparticles. Meanwhile the composite FWWO-46 can interact with water molecules easily then the others. The absorption and desorption of water molecules vary from the other composites. In the presence of water molecules on the morphology of FWWO-46 shows higher conductivity and higher sensitivity factor (Sf). At low relative humidity, water adsorption on the surface of the sample was likely the dominant factor for electronic conduction. The adsorbed water increases the surface electrical conductivity of the ceramic due to the increased charge carrier, protons in the ceramic/water system. The conductivity was further increased by the presence of pores on the sample surface. In the initial stage of water adsorption, a few water vapour molecules chemisorbed on the grain surface by a dissociative mechanism to form two surface hydroxyls per water molecule. In this chemisorbed layer charge transport occurs by the hopping mechanism. Conduction probably occurs by the Grotthus transport mechanism.
关键词： Composite,Photocatalytic Activity,Iron Tungstate,VSM,Humidity Sensors,Tungsten Trioxide
更新于2025-09-09 09:28:46
-
Surface Morphology Effects on Photocatalytic Activity of Metal Oxides Nanostructured Materials Immobilized onto Substrates
摘要： Structure, shape and surface morphology of the material are directly determined by the substrate and growth method used for material fabrication of nanostructured metal oxides. Those characteristics play a crucial role in the photocatalytic activity of the material. This paper presents a short review of some of the most recent relevant publications regarding pure and doped nanostructured metal oxides used for photocatalytic applications focusing on the structure, shape and surface morphology of the material effects on photocatalytic activity. The cases of TiO2, ZnO and CuO metal oxides as well as various semiconductors and metal doping were reviewed. It was concluded that, according to the reviewed communications, the most important surface parameters affecting photocatalytic activity are surface area, surface to volume ratio, nanocrystallites size and crystallinity regardless the material. In particular, for each material, more surface parameters may be of significance.
关键词： Surface Morphology,Photocatalytic Activity,Metal Oxides
更新于2025-09-09 09:28:46
-
Mixed-ligand strategy affording two new metal-organic frameworks: Photocatalytic, luminescent and anti-lung cancer properties
摘要： Mixed-ligand strategy afforded two new metal-organic frameworks (MOFs), namely [Ni(L)0.5(4,40-bipy)0.5(H2O)2]n (1) and [Zn2(L)(bpp)2]n (2) (H4L ? 1,3-di(30,50-dicarboxylphenyl)benzene, 4,40-bipy ? 4,40 ebipyridine and bpp ? 1,3-di(4-pyridyl)propane), which were further characterized by elemental analyses, powder X-ray diffraction analyses and single crystal X-ray diffraction analyses. Compound 1 features a 4-fold interpenetrated 3D framework with (3,4)-connected dmd-type topology, and compound 2 features a 3D complicated framework with 4-connected topology. Moreover, the photocatalytic activity of compound 1 for the degradation of methyl blue (MB) and luminescent property of compound 2 were investigated in detail. In addition, the anti-lung cancer activities of both complexes have been evaluated via the MTT assay against three human lung cancer cells A549, H1299 and PC9.
关键词： Topology,Photocatalytic activity,Mixed-ligand strategy,Luminescence
更新于2025-09-09 09:28:46