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Fabrication of novel 1D/2D V2O5/g-C3N4 composites as Z-scheme photocatalysts for CR degradation and Cr (VI) reduction under sunlight irradiation
摘要： Photocatalytic materials for environmental remediation of organic pollutants and heavy metals require not only a strong visible light response and high photocatalytic performance, but also the regeneration and reuse of catalysts. In this work, 1D/2D V2O5 nanorods/g-C3N4 nanosheets (VONRs/CNNs) composites were prepared by a facile impregnation method and employed in the degradation of a Congo red (CR) and reduction of Cr (VI) under sunlight irradiation. The as-prepared samples were studied by several characterization techniques including XRD, SEM, TEM, EDS, XPS, FTIR, UV-vis DRS and PL. Results revealed that the interface interaction between VONRs and CNNs was recognized via V2O5 nanorods loading on the surface of g-C3N4 nanosheets, improving the separation and transfer of photogenerated electron-hole pairs and restraining the recombination rate of charge carriers. As a result, the photocatalytic activity of the composites was enhanced in comparison with pure CNNs and VONRs. The photocatalytic efficiency of optimal composite (4-VONRs/CNNs) for the removal of CR (Cr (VI)) was about 9.33 (4.22) and 73.52 (19.2) times higher than that of pure CNNs and VONRs, respectively. Meanwhile, the 4-VONRs/CNNs exhibited good photocatalytic stability in recycling experiments. Such enormous enhancement in photocatalytic performance was predominantly ascribed to the efficient separation and transfer of photogenerated electron-hole pairs at the VONRs/CNNs interface imparted through the direct Z-scheme charge carrier migration mechanism. Moreover, the energy band structure and the quenching effects of different scavengers demonstrated that the electrons of CNNs and holes of VONRs with higher oxidizability and reducibility are the real participants in photocatalytic reactions.
关键词： g-C3N4 nanosheets,Z-scheme mechanism,Composites,Photocatalytic activity,V2O5 nanorods,1D/2D heterojunction
更新于2025-09-10 09:29:36
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Effect of titanium (IV) isopropoxide molarity on the crystallinity and photocatalytic activity of titanium dioxide thin film deposited via green sol–gel route
摘要： In this paper, the effect of titanium (IV) isopropoxide TTIP molarity on the crystallinity and TiO2 thin film properties deposited via green sol–gel route was reported. The green sol–gel route is a pioneering approach for eco-friendly coating where solvent is not utilized in the sol formulation. This is in contrast to the common TiO2 sol formulation where solvent is used despite the long term harmful the environment. TiO2 solution with different TTIP molarity of 0.2 M, 0.3 M, 0.4 M and 0.5 M were utilized during coating deposition. Deposition were conducted for ten times using dip coating and treated at 500 ?C (1-h). The crystalline phases and phase content were characterized using X-ray diffraction (XRD) and reference intensity ratio (RIR) equation. Crystallites size was obtained by Scherrer’s equation while coating morphologies was analyzed using scanning electron microscope (SEM). The photocatalytic activity was conducted by the degradation of methylene blue (MB) towards UV-light and visible light. At higher TTIP molarity (0.5 M), higher crystallinity of mixed anatase (～17 nm) and rutile (～29 nm) phases were obtained along with homogeneous coating (cracking and visible pore). Also, higher MB degradation were obtained at UV-light (95%) and visible-light (86%) irradiation. In conclusion, higher TTIP molarity produced TiO2 film with higher crystallinity, small crystallite size, cracking morphology thus contribute good performance in photocatalytic activity. Findings in this work shown that TiO2 thin film deposition is possible conducted without the use of solvent through optimized formulation of only precursor, acid and water. This is beneficial for the environment sustainability.
关键词： Sol–gel dipping,Titanium dioxide,Green route,Solvent free,Titanium (IV) isopropoxide,Photocatalytic activity
更新于2025-09-10 09:29:36
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Synthesis and Characterization of BaAl2O4 Catalyst and its Photocatalytic Activity Towards Degradation of Methylene Blue Dye
摘要： Hexagonal BaAl2O4 catalyst has been prepared using a gamma-ray irradiation assisted polyacrylamide gel method. The catalysts synthesized at different calcining temperatures were analyzed to insight into their effects on the structural, crystalline, surface morphology, color, optical, fluorescence and photocatalytic properties of the hexagonal BaAl2O4 catalyst. Increasing the calcining temperature has obvious influences on the crystallinity, color, optical properties and the formation of the hexagonal BaAl2O4 catalyst. The optical energy gap (Eg) value of the hexagonal BaAl2O4 catalyst increases with the increasing of calcining temperature. TEM image of the pure hexagonal BaAl2O4 catalyst shows a morphology of flake structure and aggregation. Raman spectroscopy of the pure hexagonal BaAl2O4 catalyst exhibits four luminescent background peaks at 400, 415, 428 and 445 nm mainly due to the oxygen vacancies (VO), Ba vacancies (VBa) and some color centers exists in the BaAl2O4 sample. A comparison of photocatalytic activity among samples for degradation of methylene blue (MB) dye indicates that the pure hexagonal BaAl2O4 catalyst exhibits highest photocatalytic activity under the irradiation of both visible and ultraviolet light. Based on the fluorescence experiment, electrochemical and active species tests, the high photocatalytic activity of the pure hexagonal BaAl2O4 catalyst to be related to hole (h+) and hydroxyl radical (·OH) and also to the defects in the sample.
关键词： BaAl2O4,photocatalytic activity,methylene blue,polyacrylamide gel method,calcining temperature,optical energy gap
更新于2025-09-10 09:29:36
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Impact of the anodization time on the photocatalytic activity of TiO <sub/>2</sub> nanotubes
摘要： Titanium oxide nanotubes (TNTs) were anodically grown in ethylene glycol electrolyte. The influence of the anodization time on their physicochemical and photoelectrochemical properties was evaluated. Concomitant with the anodization time, the NT length, fluorine content, and capacitance of the space charge region increased, affecting the opto-electronic properties (bandgap, bathochromic shift, band-edge position) and surface hydrophilicity of TiO2 NTs. These properties are at the origin of the photocatalytic activity (PCA), as proved with the photooxidation of methylene blue.
关键词： nanotubes,photocatalytic activity,photoelectrochemistry,titanium(IV) oxide (TiO2),fluorine doping
更新于2025-09-10 09:29:36
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Enhanced visible-light-driven photocatalytic activity of F doped reduced graphene oxide - Bi <sub/>2</sub> WO <sub/>6</sub> photocatalyst
摘要： The reduced graphene oxide‐Bi2WO6 (rGO‐BWO) photocatalysts with the different RF/O values (molar ratio of the F molar mass and the O's molar mass of Bi2WO6) had been successfully synthesized via one‐step hydrothermal method. The F‐doped rGO‐BWO samples were characterized by X‐ray diffraction patterns (XRD), field‐emission scanning electron microscopy (FE‐ESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller surface area (BET), X‐ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The results indicate that F ions had been successfully doped into rGO‐BWO samples. With the increasing of the RF/O values from 0 to 2%, the evident change of the morphology and the absorption edges of F‐doped rGO‐BWO samples and the photocatalytic activities had been enhanced. Moreover, the photocatalytic activity of F‐doped rGO‐BWO with RF/O = 0.05 were better than rGO‐BWO and the other F‐doped rGO‐BWO under 500 W Xe lamp light irradiation. The enhanced photocatalytic activity can be attributed to the morphology of the intact microsphere that signify the bigger specific surface area for providing more possible reaction sites for the adsorption–desorption equilibrium of photocatalytic reaction, the introduction of F ions that may cause the enhancement of surface acidity and creation of oxygen vacancies under visible light irradiation, the narrower band gap which means needing less energy for the electron hole pair transition.
关键词： photocatalytic activity,rGO‐Bi2WO6,fluorine doping,hydrothermal method
更新于2025-09-10 09:29:36
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Enhanced visible light photocatalytic activity of zno nanoparticles modified by cyclized polyacrynitrile
摘要： The ZnO/cyclized polyacrylonitrile (CPAN) composites were prepared by impregnation and heat treatment process. The morphology, crystal internal structure of ZnO/CPAN nanocomposites were characterized by UV-vis-diffuse reflectance spectroscope (DRS), X-ray diffraction, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activity of ZnO/CPAN was evaluated by degradation of methyl orange under xenon lamp irradiation. The DRS results indicate that the absorption of ZnO/CPAN nanocomposites in the visible region was significantly higher than that of pure ZnO nanoparticles. The TEM results show that the surface of ZnO nanoparticles is occupied by the CPAN in small amount. The results of photocatalytic experiment show that the photocatalytic activity of ZnO nanoparticles can be improved significantly by the modification of CPAN. The possible photocatalytic mechanism was also discussed.
关键词： visible light,photocatalytic activity,nanocomposite,ZnO/CPAN
更新于2025-09-10 09:29:36
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BiVO4(010)/rGO Nanocomposite and Its Photocatalysis Application
摘要： By interfacial coupling effect, the reduced graphene oxide (rGO) was constructed on (010) facet of BiVO4, which is a characteristic of the dominant separation of photogenerated electrons. The prepared samples were characterized by X-ray diffractometry and Raman spectra, which indicating that the added rGO plays an important role in regulating of V–O bond. By the X-ray photoelectron spectroscopy, it was found that the valence band value of BGO180 is increased compared with BiVO4, suggesting that there is an effective coupling present between rGO and BiVO4. Under simulated sunlight, the photocatalytic properties of BiVO4/rGO nanocomposite are evaluated by the O2 evolution. The carrier transfer effect between BiVO4 and newly formed coupling layer (BiVO4 and rGO) explains the excellent photoactivity of nanocomposite.
关键词： BiVO4,rGO,Photocatalytic activity
更新于2025-09-10 09:29:36
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Few-Layered MoS <sub/>2</sub> Nanoparticles Loaded TiO <sub/>2</sub> Nanosheets with Exposed {001} Facets for Enhanced Photocatalytic Activity
摘要： To improve the high charge carrier recombination rate and low visible light absorption of f001g facets exposed TiO2 [TiO2(001)] nanosheets, few-layered MoS2 nanoparticles were loaded on the surfaces of TiO2(001) nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the MoS2–TiO2(001) nanocomposites exhibited much enhanced photocatalytic activities compared with the pure TiO2(001) nanosheets. At an optimal Mo/Ti molar ratio of 25%, the MoS2–TiO2(001) nanocomposites displayed the highest photocatalytic activity, which took only 30 min to degrade 50 mL of RhB (50 mg/L). The active species in the degradation reaction were determined to be h t and (cid:1)OH according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% MoS2–TiO2(001) nanocomposites.
关键词： MoS2,nanocomposites,TiO2,photocatalytic activity
更新于2025-09-10 09:29:36
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Synthesis of nano-Bi <sub/>2</sub> MoO <sub/>6</sub> /calcined mussel shell composite with enhanced visible light photocatalytic activity
摘要： In this study, a new nano-Bi2MoO6/calcined mussel shell composite photocatalyst was successfully prepared via a facile solvothermal method. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-vis diffuse reflection spectroscopy (DRS) were employed to investigate the morphology, crystal structure, optical properties. It was shown that the nanometer-scaled Bi2MoO6 crystals was assembled with calcined mussel powder, and forming a similar spheroid structure. The obtained samples were displayed higher photocatalytic activities than pure Bi2MoO6 for the degradation of MB under visible-light irradiation. Among them, the Bi2MoO6/ calcined mussel shell mass ratio of 0.7 exhibited the highest activity, and the MB degradation efficiency reached up to 62.46% within 60 min. As a photocatalytic reactor, its recycling performance showed a good stability and reusability. This new composite photocatalyst material holds great promise in the engineering field for the environmental remediation.
关键词： nano-Bi2MoO6,photocatalytic activity,environmental remediation,calcined mussel shell,visible light
更新于2025-09-10 09:29:36
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Antibacterial and photocatalytic activity of anatase phase Ag-doped TiO2 nanoparticles
摘要： A simple and new solid-state molten-salt method to synthesise silver (Ag)-doped titanium dioxide (TiO2) nanoparticles for solar light-induced photocatalytic applications is examined. Ag-doped TiO2 nanoparticles with varied Ag content ranging from 3 to 10% were synthesised by a single-step molten-salt synthesis method. The effect of Ag content on the antibacterial and photocatalytic activity of nanoparticles was tested. The prepared nanoparticles were studied by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, ultraviolet–visible (UV–vis) diffusive re?ectance spectrometer (UV–vis DRS) and powder X-ray diffraction. The SEM image of nanoparticles clearly showed the presence of agglomerated spherical particles. The EDX analysis of the particles con?rmed successful doping of particles in the presence of the Ag in the particles. The doping of Ag in TiO2 produced TiO2 pure anatase phase. According to UV–vis DRS results, increasing Ag-doped content in the Ag-doped TiO2 resulted in a higher visible absorption capability of the materials. Ag doping also improved the antibacterial and photocatalytic activity of TiO2 nanoparticles. The maximum photocatalytic activity under light irradiation was observed for 5% Ag-doped TiO2.
关键词： antibacterial activity,anatase phase,photocatalytic activity,molten-salt method,Ag-doped TiO2
更新于2025-09-09 09:28:46