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Photocatalytic degradation of phenol by LaFeO3 nanocrystalline synthesized by gel combustion method via citric acid route
摘要： Focusing on the photocatalytic degradation of phenol under visible light, the synthesized lanthanum orthoferrites (LaFeO3) by gel combustion method using citric acid as sacrificial agent were investigated. With the highest reaction temperature of 200 °C, the physicochemical properties of synthesized samples were characterized by X-Ray diffraction (XRD) analysis, Brunauer–Emmet–Teller (BET), and Energy Dispersive X-Ray spectroscopy (EDS). On the other hand, UV–Vis spectroscopy analysis was carried out to determine the phenol photodegradation activities and mechanism. The results suggested the well-defined LaFeO3 nanocrystals with specific area of 28 m2 g?1 were successfully synthesized. Besides that, variations in operating parameters such as pH, catalyst dosage and initial concentration of phenol in synthetic wastewater were also examined. In conclusion, LaFeO3 nanocrystalline exhibited an exceptional photocatalytic activity for phenol degradation, thus providing a perfect alternative for pharmaceutical wastewater treatment.
关键词： Citric acid,Photocatalytic activity,Lanthanum orthoferrite,Phenol,Gel combustion
更新于2025-09-23 15:23:52
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Partially etched Bi2O2CO3 by metal chloride for enhanced reactive oxygen species generation: A tale of two strategies
摘要： Light-mediated reactive oxygen species generation with water and oxygen is generally regarded as a mild and efficient way for organic pollutants removal. However, it is highly difficult but desirable to construct a photochemical system with increased reactive oxygen species production. Herein, by using Bi2O2CO3 as a prototype, we devise a simple metal chloride-involved etching method to achieve better light absorption and charge carriers separation in a wide-band-gap semiconductor, thus giving rise to improved molecular oxygen activation. The improved photoinduced reactive oxygen species production is further verified by excellent photocatalytic degradation ability of RhB, TC and BPA under visible and ultraviolet light illumination. In addition, the metal chloride-induced strategies—heterojunction formation and cation doping—significantly affect the dynamics and transfer of carriers, which are advantageous to manipulate one-/two-electron pathway for producing reactive oxygen species.
关键词： Metal chloride,Photocatalytic,Bi2O2CO3,Reactive oxygen species,Heterojunction
更新于2025-09-23 15:23:52
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[Mo3S13]2? modified TiO2 coating on non-woven fabric for efficient photocatalytic mineralization of acetone
摘要： Improving the photocatalytic efficiency of commercial TiO2 has important significance for practical application of TiO2 based photocatalysts. A novel photocatalyst [Mo3S13]2?/TiO2 was fabricated by combining [Mo3S13]2? with commercial TiO2 by an impregnation method. This composite photocatalyst presented a remarkable enhancement on photocatalytic mineralization of acetone in comparison with commercial TiO2. The optimum loading amount of [Mo3S13]2? was 1.7wt%, which is more efficient than the Pt/TiO2 (1.5wt%). Electrochemical impedance spectroscopy (EIS) showed the smooth electron transfer pathway in [Mo3S13]2?/TiO2 composite, facilitating the photo-charges separation during the photocatalysis process. Reactive oxygen species scavenging test illustrated that superoxide radical (?O2?), hydroxyl radical (?OH) and photo-induced hole (h+) were all contributing to the acetone degradation. The [Mo3S13]2?/TiO2 photocatalyst was deposited on non-woven fabrics which showed obvious promotion on the photocatalytic degradation of acetone in comparison with pristine commercial TiO2.
关键词： TiO2,[Mo3S13]2?,Photocatalytic oxidation,VOCs degradation,Non-woven fabrics
更新于2025-09-23 15:23:52
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A novel Z-scheme Ag3VO4/BiVO4 heterojunction photocatalyst: Study on the excellent photocatalytic performance and photocatalytic mechanism
摘要： A novel three-dimensional microspheres mediator-free Z-scheme Ag3VO4/BiVO4 heterojunction photocatalyst was successfully obtained for the first time. The photocatalytic performance of the as-prepared photocatalyst was systematically examined via the photocatalytic reduction of Cr6+ and oxidation of Bisphenol S under visible-light irradiation. Among these samples, 0.24-Ag3VO4/BiVO4 exhibits the highest photocatalytic performances, the photocatalytic reduction and oxidation efficiency of 74.9 and 94.8 %, respectively, can be achieved. The enhanced photocatalytic performance is attributed to the build-in electric field assisted charge transfer between the Ag3VO4 and BiVO4, and the increasing lifetime of the charge carrier confirmed by the results of time-resolved fluorescence spectra and photoelectrochemical measures. Moreover, based on the results of free radical scavenging activity test, and EPR experiments, it has been verified that the Ag3VO4/BiVO4 heterostructures follow a typical Z-scheme charge transfer mechanism rather than conventional type-II heterojunction charge transfer mechanism. Furthermore, the theoretical understanding of the underlying mechanism was also supported, while the energy band structure, and Fermi level were systematically calculated using the density functional theory approach. The results show that a built-in electric field directed from Ag3VO4 to BiVO4 surface was established as an equalized Fermi level was reached, which benefits the separation of photogenerated charge carriers in the way of a Z-scheme charge transfer mechanism. The strategy to form the three-dimensional microspheres Z-scheme heterojunction photocatalyst may offer new insight into the Z-scheme charge transfer mechanism for applications in the field of solar energy conversion.
关键词： Bismuth Vanadate,Z-scheme heterojunction photocatalyst,photocatalytic reduction and oxidation.
更新于2025-09-23 15:23:52
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Interfacial engineering of Fe2O3@BOC heterojunction for efficient detoxification of toxic metal and dye under visible light illumination
摘要： Recent developments of small band gap semiconductor coupled bismuth carbonate (BOC) heterojunction are advantageous for photocatalysis application because of their improved solar harvesting ability and enhanced charge-carrier collection. In this work, we have developed iron (III) oxide decorated bismuth carbonate (Fe2O3@BOC) heterojunction via a simple two-step process. The developed heterojunction exhibits excellent photocatalytic activity towards reduction of carcinogenic and mutagenic Cr(VI) to nontoxic Cr(III) and degradation of toxic dye [methylene blue (MB)] under visible light illumination. Further investigation revealed that the loading of Fe2O3 nanoparticles had an impact on efficient charge carrier collection at the interface of Fe2O3@BOC heterojunctions. The unprecedented photocatalytic activity for Fe2O3@BOC1 heterojunction at room temperature could be attributed due to the enhancement in light absorption ability and suppression of electron–hole pair recombination at the heterojunction interface. In addition, reduction in efficacy of the heterojunction with increase in loading of Fe2O3 nanoparticles on BOC surface further confirms the role of interface on the modulation of photocatalytic activity. The role of photogenerated electrons and reactive oxygen species involved during photocatalytic reduction of Cr(VI) and degradation of MB was studied in detail. Moreover, recyclability experiment demonstrates that the developed photocatalyst can be reused without decay in performance. Finally, development of inexpensive prototype reactor is demonstrated towards reduction of Cr(VI) and degradation of MB under continuous flow operation. Thus, good efficacy of the developed reactor for cleaning of toxic pollutants in water makes the heterojunction (Fe2O3@BOC1) a promising photocatalyst for water purification in near future.
关键词： photocatalytic activity,charge separation,Heterojunction,toxic pollutants,visible light
更新于2025-09-23 15:23:52
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A generic strategy for preparation of TiO2/BixMyOz (M?=?W, Mo) heterojunctions with enhanced photocatalytic activities
摘要： Employment of nanoscale TiO2/BixMyOz (M = W, Mo) heterojunctions is one of the most promising strategies for improving the photocatalytic efficiency. However, the controllable synthesis and morphology modification of these heterojunctions are still highly challenging. In this work, we developed a generic approach to hydrothermally synthesize TiO2/BixMyOz heterojunctions and tailor their morphologies. The key of this strategy is to intentionally utilize the surface defects of TiO2 as highly active sites to adsorb the intermediate hydrolysis-products, which is in marked contrast to the conventionally direct precipitation methods. In the subsequent hydrothermal reactions, MO4 2- replaced the hydroxyl and nitrate radicals to form stable TiO2/BixMyOz heterojunctions, in which the second phase BixMyOz occupied the defect sites of TiO2 nanobelts. Under visible light irradiation, the photocatalytic reaction rate constant of TiO2/Bi2WO6 heterojunctions was four times higher than that of single phase Bi2WO6 nanosheets, while the photocatalytic reaction rate constant of TiO2/Bi3.64Mo0.36O6.55 heterojunctions exhibited a seven-fold increase compared with Bi3.64Mo0.36O6.55 nanopaticles. The substantial enhancement of photocatalytic activity is primarily ascribed to the matching energy band structure in the TiO2/BixMyOz heterojunctions, which is able to improve the separation efficiency of photo-generated electron-hole pairs and prolong the lifetime of charge carriers in the heterojunctions.
关键词： TiO2/Bi2MoO6 heterojunctions,photocatalytic activities,TiO2/Bi2WO6 heterojunctions,defects induction,TiO2/Bi3.64Mo0.36O6.55 heterojunctions
更新于2025-09-23 15:23:52
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Photocatalytic Activity of ZnO Nanopowders: The role of production techniques in the formation of structural defects
摘要： The effect of the type of structural defect in zinc oxide on its photocatalytic properties was studied for phenol photodegradation under UV-irradiation. It was shown that the use of different types of precursors (zinc oxalate and zinc hydroxide) for the production of zinc oxide leads to the formation of a material with the same phase composition and equal energy of the forbidden band, but different photocatalytic activities. Simultaneously, the peculiarities of the luminescence and electron spin resonance spectra indicate the formation of different types of defects in the structure of the material, namely, oxygen vacancies (Vo) in the anionic and zinc vacancies (VZn) in the cationic sublattices of zinc oxide synthesised from the zinc oxalate and hydroxide, respectively. Also, the different characteristics of the luminescence decays reveal the different recombination paths for the free charge carriers in the systems synthesised from the different precursors. The different times of the luminescence decay also confirmed the different methods of recombination of free charge carriers in systems synthesised from different precursors. It was shown that the appearance of defects in the cationic sublattice leads to a decrease in the photocatalytic activity of the material relative to phenol degradation.
关键词： vacancies,luminescence.,Photocatalytic activity,structure defects,ZnO
更新于2025-09-23 15:23:52
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Nanosheet and nanosphere morphology dominated photocatalytic & antibacterial properties of ZnO nanostructures
摘要： To address the issue of water contamination with the usage of dyes and undesired bacterial growth on food products, different ZnO nanostructures have been studied in present manuscript. XRD technique has investigated the crystal purity of ZnO nanostructures. The alteration in chemical structural parameters (bond vibration and spring constant etc.) confirms their structure level modification by fourier transform infrared spectroscopy (FTIR). The maximum efficiency of methylene blue dye degradation has been observed in nanosheet (～96.42%) as compared to nanosphere (～95.45%) & nanorod (～87.12%) morphology. In addition, the antibacterial activity of ZnO nanospheres for E. coli and S. aureus bacteria shows inhibition diameter of 10 mm & 12 mm is credited due to generation of active oxidizing agents as compared to other reported morphologies. Present studied ZnO nanomaterials embolden researchers to investigate the unexplored aspects of ZnO nanomaterials to ameliorated efficiency in photocatalytic and antibacterial applications.
关键词： Morphology,Antibacterial,Nanostructures,Photocatalytic
更新于2025-09-23 15:23:52
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Low-cost effective photocatalytic activity under visible light of pitch-based porous carbon nanofiber composites aided by zinc oxide
摘要： To explore and develop an economical, novel, and effective photocatalyst for the degradation of methylene blue (MB) under visible-light irradiation, polyacrylonitrile (PAN)/pitch-based carbon nanofibers (CNFs) with ZnO (PPZn) are successfully produced by one-step electrospinning of PAN, pitch, and zinc acetate in dimethylformamide (DMF) solution. The charge separation rate, adsorption capacity, and visible-light harvesting effects are all enhanced by the synergistic effect of PAN/pitch-based CNFs and ZnO coupling. The resulting PPZn photocatalysts exhibit excellent removal capacity of 100% of MB within 30 min and a kinetic rate constant of 0.018 min?1 under visible light. PPZn also exhibits a consistent and stable photocatalytic performance by maintaining nearly 100% removal of 15 ppm MB over 8 regeneration cycles. The PP-based CNFs in PPZn act as a charge reservoir to afford fast transport for suppressing the e?–h? recombination and high electrical conductivity induced by the pitch, thereby expanding the visible-light response. The PP(3)Zn composites demonstrate a promising potential as a low-cost photocatalyst material offering excellent photocatalytic efficiency in the visible-light spectrum.
关键词： Carbon nanofiber,ZnO,Methylene blue,Pitch,Visible light,Photocatalytic activity
更新于2025-09-23 15:23:52
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Insight into visible light-driven photocatalytic performance of direct Z-scheme Bi2WO6/BiOI composites constructed in -situ
摘要： Bi2WO6/BiOI composites with enhanced photocatalytic performance were constructed in-situ by a hydrothermal routine. The Bi2WO6/BiOI composites were studied by Brunauer -Emmett-Teller (BET), X-ray di?raction patterns (XRD), UV–Vis di?use re?ectance spectra (DRS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), surface photovoltage spectroscopy (SPS), electron spin-resonance (ESR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results support the coexistence of Bi2WO6 and BiOI in the composites. All the Bi2WO6/BiOI composites display higher separation rate of photoinduced carriers than BiOI. OH and·O2? were formed in the composite photocatalytic system. Finally, a direct Z-scheme was proposed for the Bi2WO6/BiOI composites.
关键词： Separation of photoinduced carriers,Bi2WO6,Heterojunctions,Visible light photocatalytic property,BiOI
更新于2025-09-23 15:23:52