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Visible light-driven photoelectrocatalytic degradation of Acid Yellow 17 using Sn3O4 flower-like thin films supported on Ti substrate (Sn3O4/TiO2/Ti)
摘要： This article reports a new method for preparing mixed valence tin oxide (Sn3O4) flower-like nanostructures using a microwave-assisted route. Thin-film Sn3O4/TiO2/Ti electrodes demonstrated highly efficient visible light driven photocatalytic degradation of monoazo acid yellow 17 (AY17) dye, reaching 95% color removal after 60 min at pH 2. Moreover, under low bias potential (0.5 V), the photoelectrocatalytic efficiency increased to 97% color removal and 83% removal of total organic carbon at a kinetic rate almost 3 times higher than in photocatalysis. Liquid chromatography mass spectrometry was used to identify intermediate formation, and oxidation performance was proposed for photocatalytic and photoelectrocatalytic degradation with no organics identified after 120 min of treatment. The results indicate that Sn3O4/TiO2/Ti photoelectrodes offer a simple, green method for wastewater treatment employing visible light source.
关键词： Dye degradation,Photoelectrocatalysis,Microwave-assisted hydrothermal synthesis,Sn3O4,Visible-light photocatalysis
更新于2025-11-19 16:56:35
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Rationally Designed Fe2O3/GO/WO3 Z-Scheme Photocatalyst for Enhanced Solar light Photocatalytic Water Remediation
摘要： A novel ternary Fe2O3/GO/WO3 all-solid-state Z-Scheme photocatalyst was rationally designed. Structural, morphological, optical and electronic properties of the synthesized nanocomposite were investigated by XRD, SEM, TEM, UV-vis Diffuse Reflectance and Raman spectroscopy. The results revealed the successful synthesis of the nanocomposite materials. Uniquely, double absorption edges at 2.0 and 2.3 eV for Fe2O3/WO3 and triple absorption edges at 1.5, 1.8 and 2.1 eV for Fe2O3/GO/WO3 were investigated for the first time. Lower absorption band edges dominated for both Fe2O3/WO3 and Fe2O3/GO/WO3, while higher absorption edges dominated for pure nanomaterials. The enhanced interaction among GO, Fe2O3 and WO3 matrix explained the reduction in the CB energy leading to efficient electron separation and transformation and consequently improving the photocatalytic activity. The visible light photocatalytic performance of Fe2O3/GO/WO3 nanocomposites were evaluated for degradation of methylene blue (MB) and crystal violet (CV) dyes as model water pollutants. The photocatalytic activity for degradation of both dyes was found to be greatly enhanced in the presence of ternary Fe2O3/GO/WO3 nanocomposite as compared to nanocomposite systems of Fe2O3/WO3, WO3/GO and Fe2O3/GO or pure Fe2O3 and WO3 nanomaterials. The enhancement in the photocatalytic performance of ternary Fe2O3/GO/WO3 nanocomposite was proven to be due to the all-solid-state Z-Scheme in which the photogenerated electrons in the CB of photosystem I (WO3) transferred through GO mediator and recombined with the photogenerated holes in the VB of Fe2O3 (photosystem II). So that, the electron-hole pair recombination can be suppressed in both systems. Moreover, the photocatalytic activity of the best Fe2O3/GO/WO3 nanocomposite (FGW 30) has been tested for the degradation of phenol. The results show that 95.4 % of phenol was degraded in 120 minutes. Thus, this study provides an efficient green Z-Scheme photocatalyst for water remediation utilizing solar light.
关键词： solar light photocatalysis,organic dyes degradation,all-solid-state Z-Scheme,Ternary Fe2O3/GO/WO3,phenol mineralization
更新于2025-11-14 15:26:12
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Impact of doped metals on urea-derived g-C3N4 for photocatalytic degradation of antibiotics: Structure, photoactivity and degradation mechanisms
摘要： Metal doping is an appealing modification strategy of graphitic carbon nitride (g-C3N4) to improve its photocatalytic activity. The interactions of g-C3N4 precursors with metals, however, has often been underappreciated, which can induce great impacts on g-C3N4 formation and properties. Herein, the impacts of metals (Na, K, Ca, Mg) on the morphology, structure, and photoactivity of urea-derived g-C3N4 were investigated. Our TEM and XPS results confirmed that the interactions of doped metals with urea precursors lead to the incorporation of O atoms from urea molecules into the framework of g-C3N4. Due to the synergistic effects of the metals and structural O atoms, doped g-C3N4 performed an elevated photodegradation of antibiotics under the visible light irradiation, which was attributed to the enhanced light-harvesting and reduced charge recombination. In addition, the doped metals presented uneven regulation on the band structures and morphology of g-C3N4. As a result, both superoxide and hydroxyl radicals were generated by g-CN-Na and g-CN-K, whereas, only superoxide radicals were involved in g-CN, g-CN-Ca and g-CN-Mg. Consequently, diversified photodegradation mechanisms for enrofloxacin (ENR) were observed that the g-CN, g-CN-Ca and g-CN-Mg reaction systems mainly attacked the piperazine moiety of ENR while g-CN-Na and g-CN-K provided additional photodegradation pathway by attacking quinolone core of ENR. The present work could provide new insights into further understanding of doping chemistry with g-C3N4.
关键词： Metal doping,Photocatalytic degradation of antibiotics,g-C3N4,Visible light photocatalysis
更新于2025-11-14 15:24:45
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Covalent organic framework as an efficient, metal-free, heterogeneous photocatalyst for organic transformations under visible light
摘要： Visible-light active, heterogeneous, and organic photocatalysts exhibit a more sustainable and environmentally friendly alternative to classical metal-based catalysts. Two-dimensional covalent organic frameworks (2D-COFs) with permanent porosity, columnar π-arrays and excellent stability, that can become an excellent platform for heterogeneous photocatalysis of organic transformations. Here we report a predesigned imine-based COF with electron donor and acceptor structure. And new framework possesses large surface area, high crystallinity, outstanding stability and broad absorption range in the visible-light region as well as good photoelectric response characteristics. Importantly, it was found to be a highly effective heterogeneous photocatalyst for reductive dehalogenation of phenacyl bromide derivatives and α-alkylation of aldehydes under irradiation of visible-light. In addition, the COF gave good recyclability and could be reused after a simple separation manipulation. The current present still reveals a great prospect for 2D-COFs as metal-free, heterogeneous photocatalysts for organic transformations.
关键词： visible light,photocatalysis,heterogeneous catalysis,metal-free,covalent organic frameworks
更新于2025-09-23 15:23:52
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Photocatalytic oxidation of gaseous benzene, toluene and xylene under UV and visible irradiation over Mn-doped TiO2 nanoparticles
摘要： The photocatalytic oxidation of gaseous benzene, toluene and xylene (BTX) over un-doped, 0.1 and 1 wt% Mn-TiO2 nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert gas. The photocatalytic decomposition efficiency and the oxidation products were determined using a Static Photochemical Reactor coupled with FTIR spectroscopy. BTX underwent efficient decomposition over Mn-TiO2 photocatalysts under UV irradiation, more with oxygen presence and less without oxygen. More important toluene and xylene went substantial decomposition over 0.1 mol% Mn-TiO2 under visible irradiation with oxygen presence. The main final oxidation products in the UV photocatalysis of BTX were CO2, CO and H2O, with CO2 and CO yields 4 and 2 respectively. The conversion percentage of benzene, toluene, and xylene to CO2 were 63.6%, 56.4%, 51.8%, and to CO 29%, 26.5%, 23.2%, respectively. In the visible photocatalysis of toluene and xylene the yields of CO were insignificant. Formation of carbon containing deposits on TiO2 surfaces was observed after extensive UV photocatalysis of toluene and xylene, and such by-products surface coverage may reduce the photocatalytic activity of TiO2 samples. Some aspects of the photocatalytic mechanism were examined.
关键词： Mn-doped TiO2,Visible - light photocatalysis,Photodegradation of Benzene,Indoors air pollution,Xylene,Toluene
更新于2025-09-23 15:23:52
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A sustainable solution for removal of glutaraldehyde in saline water with visible light photocatalysis
摘要： Glutaraldehyde (GA) is the most common biocide used in unconventional oil and gas production. Photocatalytic degradation of GA in brine simulating oil and gas produced water using Ag/AgCl/BiOCl composite as a photocatalyst with visible light was investigated. Removal of GA at 0.1 mM in 200 g/L NaCl solution at pH 7 was 90% after 75 min irradiation using 5 g/L of the photocatalyst. The GA removal followed pseudo-first order reaction with a rate constant of 0.0303 min?1. At pH 5 or at 300 g/L NaCl, the photocatalytic removal of GA was almost completely inhibited. Similar inhibitions were observed when adding dissolved organic carbon (from humic acid) at 10 and 200 mg/L, or Br? at 120 mg/L to the system. The removal rate of GA markedly increased with increasing pH (5-9), photocatalyst loading (2-8 g/L) and under 350 nm UV (compared to visible light). On the contrary, the removal rate of GA markedly decreased with increasing NaCl and initial GA concentrations (0-300 g/L for NaCl and 0.1-0.4 mM for GA). A quenching experiment was also conducted; electron holes (h+) and superoxide (O2?-) were found as the main reactive species responsible for the removal of GA while ?OH had a very limited effect.
关键词： saline,Glutaraldehyde,produced water,hydraulic fracturing fluid,visible light photocatalysis
更新于2025-09-23 15:23:52
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Real Time Monitoring of a UV Light-Assisted Biofunctionalization Protocol Using a Nanophotonic Biosensor
摘要： A protocol for the covalent biofunctionalization of silicon-based biosensors using a UV light-induced thiol–ene coupling (TEC) reaction has been developed. This biofunctionalization approach has been used to immobilize half antibodies (hIgG), which have been obtained by means of a tris(2-carboxyethyl)phosphine (TCEP) reduction at the hinge region, to the surface of a vinyl-activated silicon-on-insulator (SOI) nanophotonic sensing chip. The response of the sensing structures within the nanophotonic chip was monitored in real time during the biofunctionalization process, which has allowed us to confirm that the bioconjugation of the thiol-terminated bioreceptors onto the vinyl-activated sensing surface is only initiated upon UV light photocatalysis.
关键词： UV light photocatalysis,biofunctionalization,silicon on insulator,nanophotonic sensor,half antibodies
更新于2025-09-23 15:23:52
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Visible Light Driven Hydrogen Evolution by Molecular Nickel Catalysts with Time-Resolved Spectroscopic and DFT Insights
摘要： Hydrogen (H2) is a clean fuel that can potentially be a future solution for the storage of intermittent renewable energy. However, current H2 production is mainly dominated by the energy intensive steam reforming reaction, which consumes a fossil fuel, methane, and emits copious amounts of carbon dioxide as one of the byproducts. To address this challenge, we report a molecular catalyst that produces H2 from aqueous solutions, is composed of affordable, earth-abundant elements such as nickel, and has been incorporated into a system driven by visible light. Under optimized conditions, we observe a turnover number of 3880, among the best for photocatalytic H2 evolution with nickel complexes from water?methanol solutions. Through nanosecond transient absorption, electron paramagnetic resonance, and UV?vis spectroscopic measurements, and supported by density functional theory calculations, we report a detailed study of this photocatalytic H2 evolution cycle. We demonstrate that a one-electron reduced, predominantly ligand-centered, reactive Ni intermediate can be accessed under visible light irradiation using triethylamine as the sacrificial electron donor and reductive quencher of the initial photosensitizer excited state. In addition, the computational calculations suggest that the second coordination sphere ether arms can enhance the catalytic activity by promoting proton relay, similar to the mechanism among [FeFe] hydrogenases in nature. Our study can form the basis for future development of H2 evolution molecular catalysts that incorporate both ligand redox noninnocence and alternative second coordination sphere effects in artificial photosynthetic systems driven by visible light.
关键词： Proton relay,Second coordination sphere,DFT calculations,Time-resolved spectroscopy,Visible light photocatalysis,Hydrogen evolution,Molecular nickel catalysts
更新于2025-09-23 15:23:52
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Synthesis of silver phosphate/sillenite bismuth ferrite/graphene oxide nanocomposite and its enhanced visible light photocatalytic mechanism
摘要： In the present work, silver phosphate/sillenite bismuth ferrite/graphene oxide (Ag3PO4/Bi25FeO40/GO) nanocomposite has been successfully fabricated via hydrothermal strategy and ultrasound precipitation treatment. Afterwards, physicochemical properties of as-obtained composite were studied through X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), Brunauer-Emmett-Teller (BET) surface areas, vibrating sample magnetometer(VSM) measurements. Meanwhile, Linear sweep voltammetry (LSV), Mott-Schottky (M-S), Transient photocurrent-curves and electrochemical impedance spectroscopy (EIS) measurements were measured to investigate the photoelectrochemical properties. Besides, the degradation efficiency of Rhodamine B was as the evaluation of PC efficiency, which could reach 96.9% after 75min illumination. The results indicated that spherical Ag3PO4 and Bi25FeO40 crystallographic particles were integrated with GO and the enhanced PC performance can be attributed to significantly visible light absorbance and charge separation efficiency. Furthermore, to distinguish the contribution of reactive species including ?O2?, ?OH, H2O2, h+ and e?, several scavenger experiments have been conducted. Noticeable, the Ag3PO4/Bi25FeO40/GO nanocomposite has magnetic because of the integration with Bi25FeO40. Eventually, the possible photocatalytic performance mechanism of Ag3PO4/Bi25FeO40/GO was proposed.
关键词： Ag3PO4/Bi25FeO40/GO,Visible light photocatalysis,Photocatalytic performance mechanism,Magnetic nanocomposite
更新于2025-09-23 15:22:29
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Particularities of trichloroethylene photocatalytic degradation over crystalline RbLaTa2O7 nanowire bundles grown by solid-state synthesis route
摘要： This is the first report on synthesis and photocatalytic activity for trichloroethylene (TCE) degradation under simulated solar light over RbLaTa2O7 layered perovskites with predominant nanowire or platelet morphologies. SEM images witnessed that the one step thermal treatment at 1200 °C lead to formation of RbLaTa2O7 nanowires with diameter of 80~320 nm and several microns in length associated in bundles and sharp-edged, merged platelets (minor phase). The two-step annealing at 950 °C and 1200 °C resulted in decrease of wires bundle population and increase in that of platelets merged in facetted particles. The RbLaTa2O7 nanowires are made of by well-aligned atomic rows with preferred orientation toward the c-axis, relatively free of defect. High density of hydroxyl groups on the sample calcined in mild conditions (RbLaTa_01) favors the photo mineralization of TCE. In contrast, the activity of RbLaTa_02 annealed in harsh conditions (950 and 1200 oC), poor in surface hydroxyl groups, remained modest. The weak surface basicity directed the reaction mainly to generation of intermediate chlorinated compounds. Pd and Au were supported on RbLaTa2O7 perovskites as an alternative strategy to boost the removal of chlorinated pollutants by combining photocatalytic (mineralization) and catalytic (hydrodechlorination, HDC) processes. The mineralization of TCE to Cl- was drastically hindered in presence of methanol due to quenching of ?OH radicals by alcohol. The results suggested that the density of RbLaTa2O7 surface hydroxyl groups is essential for photo mineralization of TCE whereas the surface carbonate is beneficial for the formation of intermediate chlorinated product.
关键词： solid state reaction,layered perovskites,trichloroethylene,simulated solar light,photocatalysis
更新于2025-09-23 15:21:21