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Bi-component synergic effect in lily-like CdS/Cu <sub/>7</sub> S <sub/>4</sub> QDs for dye degradation
摘要： CdS has attracted extensive attention in the photocatalytic degradation of wastewater due to its relatively narrow bandgap and various microstructures. Previous reports have focused on CdS coupled with other semiconductors to reduce the photocorrosion and improve the photocatalytic performance. Herein, a 3D hierarchical CdS/Cu7S4 nanostructure was synthesized by cation exchange using lily-like CdS as template. The heterojunction material completely inherits the special skeleton of the template material and optimizes the nano-scale morphology, and achieves the transformation from nanometer structure to quantum dots (QDs). The introduction of Cu ions not only tuned the band gap of the composites to promote the utilization of solar photons, more importantly, Fenton-like catalysis was combined into the degradation process. Compared with the experiments of organic dye degradation under different illumination conditions, the degradability of the CdS/Cu7S4 QDs is greatly superior to pure CdS. Therefore, the constructed CdS/Cu7S4 QDs further realized the optimization of degradation performance by the synergic effect of photo-catalysis and Fenton-like catalysis.
关键词： Fenton-like catalysis,photocatalysis,CdS/Cu7S4,ion exchange,quantum dots,dye degradation
更新于2025-09-19 17:15:36
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Study of optical and electrical property of NaI-doped PPy thin film with excellent photocatalytic property at visible light
摘要： Conductive polymers perform as a new class of very active photocatalysts under visible light. Among them, polypyrrole (PPy) is one of the most promising conjugated polymers with a wide range of applications. PPy and doped PPy were synthesized on glass plate in thin film form by a facile simple successive ionic layer adsorption and reaction method. Polypyrrole is doped with dodecyl benzene sulphonic acid, toluene sulphonic acid, hydrochloric acid, sodium iodide (NaI), citric acid (commercial) and citric acid (lemon). The synthesized thin film was well characterized using UV–visible spectrophotometer, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and photoluminescence (PL). The electrical conductivity was measured by Hall effect measurements. Among various organic and inorganic acid dopants, NaI-doped PPy thin film exhibited narrow band gap and has excellent ability to absorb light in red region of the spectrum. NaI-doped PPy thin film showed higher conductivity when compared to other dopants. A lower PL intensity of NaI-PPy thin film indicates higher electron–hole pair separation efficiency. The photocatalytic activities of PPy thin film and NaI-doped PPy thin film on rhodamine 6G dye under visible light were systematically investigated. NaI-doped PPy thin film had better degradation efficiency than PPy due to its higher electron–hole pair separation efficiency.
关键词： Dye degradation,Polypyrrole,Rhodamine 6G,Thin film
更新于2025-09-19 17:15:36
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BWO nano-octahedron coupled with layered g-C3N4: An efficient visible light active photocatalyst for degradation of cationic/anionic dyes, and N2 reduction
摘要： The challenges like the removal of organic pollutants from the wastewater, and photocatalytic reduction of N2 using solar energy are achievable by stable, low cost, and a visible light active semiconductor mediated photocatalysis. A novel 0.4BWO/g-C3N4 heterostructure achieves excellent degradation of cationic/anionic dyes and N2 reduction under visible light illumination. The 0.4BWO/g-C3N4 exhibits 99.8% degradation efficiency towards the degradation of rhodamine B (RhB), which is 2.2-fold compared to commercial catalyst Degussa P25. 0.4BWO/g-C3N4 composite also efficiently degraded AV7, IC, DB 71 dyes and photo-reduce N2 to NH3. The incorporation of BWO nano-octahedron into the g-C3N4 network suppress the recombination of photogenerated electron-hole pairs and follow Z-scheme electron transfer pathway in 0.4BWO/g-C3N4 heterostructure. The notable separation of electron-hole pairs is well described by photoluminescence, time-resolved fluorescence, and impedance spectroscopy study. The finding presented here provides new insight into typical design and engineering of a stable and visible light active heterostructure for degradation of dyes and N2 reduction.
关键词： Photocatalyst,N2 reduction,Bi3.84W0.16 O6.24,Microwave synthesis,Dye degradation
更新于2025-09-16 10:30:52
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Modification of geopolymer with size controlled TiO2 nanoparticle for enhanced durability and catalytic dye degradation under UV light
摘要： Geopolymer- a silica alumina-based polymer has attracted generous amount of interest since the last decades as a promising alternative binder to ordinary Portland cement (OPC) in the construction sector. Proper utilization of industrial waste (Fly ash) and their functionality enhancement is explored in the present exertion by incorporating titanium oxide (TiO2) nanoparticle with different size in it. Along with the development of advanced building composite photocatalytic ability of the synthesized product was also assessed. Rutile phase TiO2 NPs were synthesized hydrothermally and annealed at different temperatures which result in differences in their overall size. Different materials characterization techniques have been carried out for confirmation of phase, functional bond, binding energy, and morphology respectively. Geopolymeric (GT) composites (GT30, GT50, and GT100) were prepared at ambient temperature using this size-variant TiO2 NPs in fly ash and alkali activator. Integration of TiO2 nanoparticles (5%) enhances mechanical properties where the optimized composite GT30 shows the maximum compressive (53.59MPa) and tensile strength (6.8MPa). Mercury Intrusion porosimetry (MIP) and atomic force microscope (AFM) studies indicate that TiO2 nanoparticles of 30 nm (T30 NPs) reduce porosity and roughness of the structure, thus lead to densified matrix and high durability performances. Additionally, GT30 mortar has low water absorption capacity as T30 NPs decrease the apparent volume of permeable voids in its matrix. Degradation of Methylene Blue (MB), a model contaminant was investigated under ultraviolet (UV) light illumination. T30 NPs (1mg) and GT30 (5mg) are found to degrade >95% dye solution within 90 mins towing to the high surface area of TiO2 NPs and free radical generation. Such outcomes are well fitted in the Langmuir–Hinshelwood first-order rate model. These results will pave the way to explore industrial waste; fly ash in geopolymer for the excellent durability and wastewater treatment through dye degradation under UV light illumination with the aid of TiO2 NPs.
关键词： Strength and durability,Geopolymer,Dye degradation.,TiO2 NPs
更新于2025-09-16 10:30:52
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Pyrolysis‐Synthesized g‐C <sub/>3</sub> N <sub/>4</sub> /Nb <sub/>2</sub> O <sub/>5</sub> Nanocomposite for Enhanced Photocatalytic Activity under White LED Light Irradiation
摘要： The design and fabrication of highly active visible-light-driven photocatalysts have been received considerable attention in recent years. However, individual component-based photocatalysts are limited in their use because of the high recombination of photoinduced carriers and poor chemical stability. Herein, the Z-scheme-originated photocatalytic activity of in-situ deposited Nb2O5 NPs on the plane surface of carbon nitride (g-C3N4) nanosheets (i. e. CN-NbO) heterostructures was studied using a simple thermal pyrolysis method. The as-synthesized photocatalysts distinctly manifested efficient white light-emitting diode (LED) irradiation toward organic malachite green (MG) dye degradation and photocatalytic hydrogen generation. The CN-NbO heterostructure showed a faster degradation rate of the MG dye and a higher photocatalytic hydrogen evolution rate. In addition, the plausible Z-scheme photocatalytic mechanism for photocatalytic hydrogen production under LED light irradiation was discussed. Photoelectrochemcial studies showed that the superior photoactivity of CN-NbO heterostructure is mainly a result of the suitable alignment of the band edge positions, which diminish carrier recombination and facilitate efficient interfacial charge transport at their interface. This study provides an ideal method for in-situ fabrication of novel two dimensional/one dimension-based photocatalysts with high activity and stable performance for photocatalytic hydrogen generation.
关键词： Dye degradation,Hydrogen evolution,Nanoparticles,Photocatalyst,LED irradiation,Layered materials
更新于2025-09-11 14:15:04
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Gold Nanoclusters Enhanced Photocatalytic Property of Bismuth Oxychloride
摘要： This paper have synthesized bismuth oxychloride (BiOCl) nano-plate (BNS) by hydrothermal method and fabricated BiOCl-gold nanoclusters (Au NCs) heterostucture nanomaterials (BANC) through electrostatic interaction. X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy characterizations indicate Au NCs successfully modified on BNS. The small energy gap makes Au NCs suitable for absorbing sunlight, while staggered energy bands between Au NCs and BiOCl could effectively separate electrons and holes, resulting in enhanced photocatlytic performance. Actually, under simulated sunlight irradiation, BANC could completely degrade rhodamine B within 30 minutes. the photostability test showed that the structure of BNAC did not changed after irradiation.
关键词： Electron transfer,Gold nanoclusters,Bismuth Oxychloride,Photocatalysis,Dye Degradation
更新于2025-09-10 09:29:36
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Pt/TiO2 nanotube photocatalyst – Effect of synthesis methods on valance state of Pt and its influence on hydrogen production and dye degradation
摘要： Direct conversion of solar energy into clean fuels is emerging as an efficient way for the future energy generation and solving environmental issues. Especially, photocatalytic splitting of water into H2 under solar light irradiation is one of the best techniques for clean energy production. Also, decomposition of organic pollutants using solar light is an urgent need to protect the environment. Hence, in the present study, we studied Pt-TiO2 nanotubes based composites for H2 generation and methyl orange dye degradation under solar light irradiation and compared the effect of deposition methods namely photo-deposition and chemical reduction methods. We have achieved the highest rate of H2 generation activity compared to other Pt-TiO2 based composite photocatalysts reported previously, and it is ≈ 173. mmol. h-1.g-1 cat for both photo-deposited and chemically reduced Pt/TiO2 nanotubes. This is about 46.8 folds higher than the pristine TiO2 nanotubes at the same experimental conditions. The selected catalysts were tested for degradation of methyl orange dye, where the catalyst prepared by chemical reduction method showed improved activity (94% degradation in 30 min) compared to the one which is prepared by photo-deposition method (50.5% degradation in 30 min). XPS analysis revealed that the photo-deposited catalyst consist only metallic Pt?, while the chemical-reduction yielded Pt with multiple oxidation states, Pt?, Pt2+ and Pt4+.
关键词： dye degradation,photo-deposition,chemical reduction,Solar energy,hydrogen production,photocatalysis
更新于2025-09-10 09:29:36
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Recent development of g-C3N4-based hydrogels as photocatalysts: A minireview
摘要： Solar-driven photocatalysis using graphitic carbon nitride (g-C3N4) is considered the most promising approach for the generation of H2 from water, degradation of organic pollutants, and reduction of CO2. However, bulk g-C3N4 exhibits several drawbacks, such as low specific surface area, high defect density, and fast charge recombination, which result in low photocatalytic performance. Construction of 3D porous hydrogels for g-C3N4 through nanostructural engineering is a rapid, feasible, and cost-effective technique to improve the adsorption capability, stability, and separability of the hydrogel composite; to increase the number of active sites; and to create an internal conductive path for facile charge transfer and high photocatalytic activity. This minireview summarizes the recent progresses in photocatalytic water splitting and dye degradation using g-C3N4-based hydrogels with respect to the state-of-the-art methods of synthesis, preparation, modification, and multicomponent coupling. Furthermore, comprehensive outlooks, future challenges, and concluding remarks regarding using g-C3N4-based hydrogels as highly efficient photocatalysts are presented.
关键词： water splitting,hydrogels,photocatalysts,dye degradation,g-C3N4
更新于2025-09-10 09:29:36
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Nanoscale Kirkendall effect driven Au Decorated CdS/CdO Colloidal Nanocomposites for Efficient Hydrogen Evolution, Photocatalytic Dye Degradation and Cr (VI) Reduction
摘要： The design of a facile and scalable method to synthesize solar light driven photocatalyst to generate H2 from water and degradation of toxic dyes from waste water is highly challenging field of research. Here, we are reporting a one pot synthesis of CdS/CdO colloidal nanocomposite with variable amount of CdS thickness and finally CdS nanoring. Different outward diffusion rate of oxygen and inward diffusion rate of sulphur ions generates hollow CdS/CdO nanocomposite based on nanoscale Kirkendall effect. Au nanoparticles (NPs) have been selectively deposited over CdS. Proper band alignment among CdO, CdS and Au results in a Z-type photocatalyst. Efficient spatial charge separation and large surface area lead to high photocatalytic dye degradation and Cr (VI) reduction in water. The amount of Cd in purified water is lesser than 0.003 ppm which maintains world Health Organization (WHO) guideline. The as developed catalyst is also active for generation of H2 from water in presence of solar light irradiation. Our present work may provide a promising way to fabricate an efficient photocatalyst for dye degradation and solar to fuel energy conversion using semiconductor (CdO)-semiconductor (CdS)-metal (Au) nanocomposite.
关键词： Dye Degradation,Hollow Nanocomposite,Kirkendall Effect,Z-scheme,H2 Production,Cr (VI) Reduction
更新于2025-09-10 09:29:36
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Fabrication of flexible MIL-100(Fe) supported SiO2 nanofibrous membrane for visible light photocatalysis
摘要： Core/shell structured SiO2/MIL-100(Fe) fibrous membrane was prepared for photocatalytic degradation of dyes. The metal organic framework shells of MIL-100(Fe) were decorated on electrospun SiO2 nanofiber surface through layer-by-layer assembly. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy tests confirmed the successful synthesis of the MIL-100(Fe) nanoparticles. The formed SiO2/MIL-100(Fe) catalysts exhibited high catalytic activity towards degradation of Rhodamine B under visible light irradiation. The photocatalytic activity remained above 80% within 90 min illumination after three cycles. Due to the easy preparation and high photocatalytic performance, as well as convenient collection for reuse, the obtained SiO2/MIL-100(Fe) membranes are promising catalysts for practical application.
关键词： Layer-by-layer assembly,Visible light,SiO2/MIL-100(Fe),Dye degradation,Photocatalysis
更新于2025-09-09 09:28:46