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AIP Conference Proceedings [Author(s) PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON CURRENT PROGRESS IN MATHEMATICS AND SCIENCES 2017 (ISCPMS2017) - Bali, Indonesia (26–27 July 2017)] - Ag/Fe3O4/CuO/ZnO incorporated NGP materials: Visible light driven photocatalysts for the degradation of water pollutants
摘要： Ag/Fe3O4/CuO/ZnO/nanographene platelets (NGP) composites with different NGP loadings were synthesized in the present study using a simple hydrothermal method. The photocatalytic activities of the prepared Ag/Fe3O4/CuO/ZnO/NGP composites were then studied for their ability to degrade different kinds of dyes in aqueous solutions under visible light irradiation. The X-ray diffraction (XRD) results indicate a face-centered cubic structure for Ag, a cubical spinel structure for Fe3O4, a monoclinic structure for CuO, and a hexagonal wurtzite structure for ZnO. Furthermore, a graphite-like structure could be detected for NGP. The thermal stability of the samples was evaluated by TGA; the results further confirm the good agreement between the actual and theoretical (5, 10, and 15 wt.%) weight loadings of NGP in the samples. Ultraviolet–visible (UV–Vis) absorbance spectroscopy was used to analyze the optical properties of the prepared samples; a surface plasmon resonance (SPR) phenomenon could be detected around ~ 440 nm and after the addition of NGP, the absorption band shifted to the visible light region. The ternary Ag/ Fe3O4/CuO/ZnO/NGP composites exhibit a significantly enhanced photocatalytic activity than either Ag/ Fe3O4/CuO/ZnO or Fe3O4/CuO/ZnO in degrading a methylene blue (MB) dye in an aqueous solution. When the NGP loading was 10 wt.%, the composites displayed the highest photocatalytic activity. The Ag/ Fe3O4/CuO/ZnO/NGP could efficiently degrade a variety of organic dyes, such as MB, Congo red (CR), and methyl orange (MO) under visible light irradiation. The species active in the degradation process were found to be the holes. More importantly, Ag/ Fe3O4/CuO/ZnO/NGP composites demonstrated good stability and reusability in repetitive photocatalytic activity processes.
关键词： visible photocatalysis,NGP,Fe3O4,Ag,ZnO
更新于2025-09-23 15:23:52
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Photocatalytic degradation of yellow 2G dye using titanium dioxide/ultraviolet A light through a Box–Behnken experimental design: Optimization and kinetic study
摘要： Yellow 2G (Y2G), a type of anionic, synthetic monoazo dye that is widely used in household applications, textiles, and food industries, has been found to have cardiovascular and neurological effects on all living beings. In the present study, heterogeneous photocatalytic degradation of commercial Y2G was conducted using pure titanium dioxide (TiO2) in a batch reactor system under ultraviolet A (UVA) light for 180 min. TiO2 dosage, pH, and initial Y2G concentration were the three experimental parameters selected and studied to obtain preliminary information about the photocatalytic activities within a specified range. The Box–Behnken design method (BBD) was used to determine optimal values of the results using the above parameters of Y2G photocatalysis under response surface methodology (RSM). The optimum conditions were 0.914 g L?1 TiO2, pH 3.45, and an initial Y2G concentration of 20 mg L?1. The Y2G degradation efficiency was 96.19% using a second-order polynomial equation with R2 = 0.999. The experimental results also showed that the photocatalytic process could be successfully explained using the modified Langmuir–Hinshelwood model, where kc and KLH were 0.787 mg L?1 min and 0.010 L mg?1, respectively.
关键词： photocatalysis,Box–Behnken design (BBD),optimization,Yellow 2G (Y2G) dye,response surface methodology (RSM)
更新于2025-09-23 15:23:52
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141 Induction Heating of TiO 2 Coating on SS Substrate for Photocatalysis 2016 60 3 Induction Heating Consolidation of TiO 2 Sol-Gel Coating on Stainless Steel Support for Photocatalysis Applications
摘要： A high-frequency induction heater was used to sinter titanium dioxide thin film on stainless steel plates with the aim of being used as photo-electrodes in wastewaters treatment. To validate the use of this sintering technique, the electrodes were prepared using sol-gel and dip-coating, followed by two different annealing processes for comparison: a conventional furnace and a high-frequency induction heating. To characterize the electrodes, X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical and photocatalysis tests were performed. Anatase and rutile phases were obtained for both annealing techniques. A more regular surface morphology was achieved via the induction heating (IH) treatment at 300 oC. The impedance study showed a lower resistance of IH samples, representing an improvement in the charge carrier separation and its fast transfer to the surface of the electrode. The photo-oxidation of methylene blue exhibited a higher degradation compared with the conventional furnace samples prepared in this study.
关键词： Photocatalysis,Azo dye,Coatings,Electrochemical techniques,Titanium dioxide,Induction heating sintering
更新于2025-09-23 15:23:52
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Improved charge separation of NiS nanoparticles modified defect-engineered black TiO2 hollow nanotubes for boosting solar-driven photocatalytic H2 evolution
摘要： NiS nanoparticles (NPs) modified black TiO2 hollow nanotubes (NBTNs) are successfully synthesized via surface hydrogenation and facile solvothermal method. The unique structure with intensified surface and interface characteristic endow NBTNs with more catalytic sites, and increase charge carrier separation efficiency with a extended charge lifetime, overwhelmingly promoting its photocatalytic performance. The resultant NBTNs possess a relatively high surface area and pore size of ~89 m2 g-1 and ~9.8 nm, respectively. The resultants NBTNs exhibit an excellent solar-driven photocatalytic hydrogen rate (3.17 mmol h-1 g-1), which almost as high as that of Pt as cocatalyst, in which the apparent quantum (AQE) yield of 5.4 % (420 nm) is recorded for the NBTNs sample. Moreover, the turnover number (TON) can be up to 116000 within 48 h. And the turnover frequency (TOF) is 2400 for NiS. This novel strategy could provide a better understanding of cocatalyst photocatalytic mechanism, and a scheme simultaneously regulating the morphology and structure of photocatalyst for promoting H2 generation.
关键词： Mesoporous TiO2 nanotube,Oxygen vacancy defect,NiS cocatalyst,Photocatalysis,Ti3+ self-doping
更新于2025-09-23 15:23:52
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Visible light driven TaON/V2O5 heterojunction photocatalyst for deep elimination of volatile-aromatic compounds
摘要： E?ciently separating carriers is the major challenge for degrading stable volatile-aromatic compounds by photocatalysis. Here, we propose using TaON to modify V2O5 to construct heterojunction for improving the charge separation e?ciency. The 5 wt% TaON/V2O5 exhibited the optimal photocatalytic activity in degradation of toluene, reaching to 40% mineralization ratio after 30 h irradiation, which was 2.1 and 1.5 times higher than TaON and V2O5, respectively. The enhanced photocatalytic activity was mainly ascribed to the improved separation e?ciency of carriers by the interface electric ?eld of heterojunction. The mass spectrum and electron paramagnetic resonance analyses distinctly demonstrated that the toluene was ?rst oxidized by OH to generate cyclohexane-1,2,3,4,5,6-hexaol. Then, it reacted with O2? and h+ to change into xylose and methoxyacetaldehyde until they were mineralized to CO2.
关键词： TaON/V2O5 heterojunction,Pollutant elimination,Volatile-aromatic compounds,Photocatalysis
更新于2025-09-23 15:23:52
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Facile assembly of g-C3N4/Ag2CO3/graphene oxide with a novel dual Z-scheme system for enhanced photocatalytic pollutant degradation
摘要： In this study, ternary catalyst g-C3N4/Ag2CO3/graphene oxide was synthesized through a simple chemical precipitation method at room temperature. The CN/AC/GO composite was employed to degrade antibiotics under visible light irradiation. And the results indicated that the composite possessed excellent photocatalytic performance, which could remove 81.6% tetracycline (TC) after 60 min of irradiation. The PL, EIS, PC and UV–vis DRS tests demonstrated that enhanced photocatalytic e?ciency could be attributed to rapid charge transfer, low recombination rate of photo-induced electron-hole pairs, as well as superior light absorption capability. Moreover, three-dimensional excitation-emission matrix ?uorescence spectra (3D EEMs) were employed to further grasp the behaviors of TC molecules in the process of degradation reaction. In addition, the liquid chromatography-mass spectrometry (LC-MS) was carried out to explore the intermediates during the photocatalytic reaction. Meanwhile, the in?uences of initial TC concentration, light source, supporting electrolytes and water sources were explored from the perspective of practical application. Furthermore, the appearance of a small amount of Ag nanoparticles (NPs) not only accelerated the charge transfer, but also improved the stability of catalyst. The composite also possessed high stability and reusability, which were essential in practical application.
关键词： g-C3N4,Double Z-scheme mechanism,Sewage treatment,Photocatalysis
更新于2025-09-23 15:23:52
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Self-hybridized coralloid graphitic carbon nitride deriving from deep eutectic solvent as effective visible light photocatalysts
摘要： The room temperature deep eutectic solvent (DES) is demonstrated as an ideal precursor to prepare self-hybridized graphitic carbon nitride (g-C3N4) for the first time, for its special components, randomly reorganized molecules and extensive hydrogen bonds. In this work, by adjusting the proportion of urea and ammonium thiocyanate in the precursor DES, the self-hybridized coralloid g-C3N4, stacked by a mass of double-layer g-C3N4/g-C3N4 nanocages, were prepared without any templates. Compared to conventional g-C3N4 prepared using melamine, urea and AT as precursors, the improved charge transfer between the interfaces of the self-hybridized g-C3N4 has been demonstrated, which is attributed to the well-matched electronic band structures of the two g-C3N4 species, the abundant 2D/2D interfacial contact and increased photocatalytic active sites. As expected, it exhibits highly enhanced photocatalytic activity, which is among the best g-C3N4 photocatalysts without doping any other elements.
关键词： G-C3N4/g-C3N4 heterojunction,Graphitic carbon nitride,Photocatalysis,Nanocages,Deep eutectic solvents
更新于2025-09-23 15:23:52
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Photocatalytic oxidation of thiophene over cerium doped TiO2 thin film
摘要： Samples of TiO2 and TiO2 doped with 2% and 8% cerium ions were prepared by a sol-gel method and used as photocatalysts for the oxidation of vaporized thiophene. X-ray diffraction patterns showed a mixed phase of anatase and rutile for TiO2, while 2%Ce/TiO2 and 8%Ce/TiO2 were dominated by the anatase phase. As seen in the transmission electron microscopy image, the particle size of Ce/TiO2 was about 10 nm which was smaller than the undoped TiO2. The extended x-rays absorption fine structures revealed the substitutional effect of cerium in the TiO2 structure. Cerium-doped TiO2 exhibited a smaller photocurrent compared to that of TiO2, which suggested the electrons were trapped by cerium ions. In situ diffuse reflectance infrared spectroscopy under UV irradiation and x-ray photoemission spectroscopy were used to investigate the photocatalytic oxidation of thiophene on the prepared catalysts. Doping of cerium ions in TiO2 resulted in an enhanced adsorption of thiophene on the catalyst surface. The oxidation products of carboxylic acid with small amounts of sulfate ions were observed. As seen from the infrared absorption spectrum, 2%Ce/TiO2 and 8%Ce/TiO2 exhibited higher photocatalytic activity than those of the undoped TiO2.
关键词： Thiophene oxidation,Thin film,Cerium,Photocatalysis,Titanium dioxide
更新于2025-09-23 15:23:52
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Diversity of TiO <sub/>2</sub> : Controlling the Molecular and Electronic Structure of Atomic-Layer-Deposited Black TiO <sub/>2</sub>
摘要： Visually black, electrically leaky, amorphous titania (am-TiO2) thin films were grown by atomic layer deposition (ALD) for photocatalytic applications. Broad spectral absorbance in the visible range and exceptional conductivity are attributed to trapped Ti3+ in the film. Oxidation of Ti3+ upon heat treatment leads to a drop in conductivity, a color change from black to white and crystallization of am-TiO2. ALD grown black TiO2, without any heat treatment, is subject to dissolution in alkaline photoelectrochemical conditions. The best photocatalytic activity for solar water splitting is obtained for completely crystalline white TiO2.
关键词： atomic layer deposition,photocatalysis,titanium dioxide,protecting overlayers,crystallization,oxide defects,water splitting
更新于2025-09-23 15:23:52
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Photo-refreshable electrochemical sensor based on composite electrode of carbon nanotubes and TiO2 nanoparticles
摘要： Surface fouling and passivation on the electrode during electrochemical process is a major challenge for the practical applications of electrochemical sensors. Herein, a photo-refreshable electrochemical sensor was presented based on carbon nanotubes/TiO2 nanoparticles (CNTs/TiO2-NPs) composite electrode, which not only exhibits high electrochemical activity towards the determination of 5-hydroxytryptamine and dopamine, but also displays excellent reproducibility in the surface electrochemical monitoring without damaging microstructure. The linear range for 5-hydroxytryptamine determination is 0.5-400 μM (R=0.991) under UV light irradiation with a detection limit of 0.47 μM (S/N=3). The CNTs/TiO2-NPs electrode also shows excellent response to dopamine, with the linear range of 0.05 μM to 100 μM and a detection limit of 0.022 μM (S/N =3). The high performance of this photo-refreshable electrochemical sensor should be attributed to the excellent photocatalytic activity of the TiO2-NPs and the high electrochemical activity of CNTs.
关键词： carbon nanotubes,photocatalysis,TiO2 nanoparticles,electrochemical sensors,surface fouling
更新于2025-09-23 15:22:29