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Ag1.69Sb2.27O6.25 coupled carbon nitride photocatalyst with high redox potential for efficient multifunctional environmental applications
摘要： Most photocatalysts cannot exhibit high efficiency to remove both gaseous and aqueous pollutants due to the limitation of redox potential and chemical property of photocatalyst itself, which will hinder the broad application of the photocatalysts. Herein, silver antimonite (Ag1.69Sb2.27O6.25) is coupled with polymeric carbon nitride (CN) as efficient photocatalyst for various environmental remediation reactions. The UV-visible light adsorption spectra, valence band X-ray photoelectron spectroscopy, and electron spin resonance spectra of different photogenerated radicals have confirmed that the transfer of electrons and holes have high redox potential to produce reactive O2?- and OH?. The Ag1.69Sb2.27O6.25 coupled CN photocatalyst produces much enhanced activity in removing various pollutants in that it exhibits about 15 folds as CN in mineralizing gaseous isopropanol into CO2, 5 folds as Ag1.69Sb2.27O6.25 in destructing aqueous oxytetracycline hydrochloride, and 10 folds as Ag1.69Sb2.27O6.25 in decoloring methylene blue under the irradiation of visible light. Control experiments in presence of scavengers p-benzoquinone and coumarin have revealed that both electrons and holes in heterojunctions participate in degradation reactions, which induce the much enhanced photocatalytic activity in removing pollutants. This study provides a facile strategy to design photocatalysts for efficient multifunctional environmental applications.
关键词： Heterojunction,Photocatalysis,Photodegradation,Silver antimonites,environmental remediation
更新于2025-11-14 17:04:02
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Study on the enhancement of photocatalytic environment purification through ubiquitous-red-clay loading
摘要： Tungsten oxide (WO3) is regarded as a promising visible-light-sensitive photocatalyst, but its activity is not high. Further enhancement of its activity has been anticipated using techniques such as loading of a cocatalyst to apply the oxide to indoor environmental remediation; Pt has been reported as a good cocatalyst for WO3 photocatalysis. However, Pt is precious and expensive metal. Thus, in this study, we sought to find a ubiquitous cocatalyst and suitable photocatalyst system. As a result, this study revealed that loading a ubiquitous material of red-clay enhanced WO3 photocatalytic activity remarkably. As photocatalyst samples, mixtures consisting of the clay and WO3 with different weight ratios were prepared using a simple kneading method. Their photocatalytic activity was evaluated from decomposition of harmful organic contaminant, 2-propanol into CO2 under visible-light irradiation. The WO3 with 10% of the clay loading showed the highest activity among the samples and much higher activity than pure WO3. This higher activity might derive from the clay’s promotion of H2O2 decomposition and charge separation (holes and electrons). The H2O2 was generated from photocatalytic O2 reduction. This formation and accumulation on the pure WO3 surface led to decreased activity.
关键词： TiO2,Zeolite,Natural mineral,Optical absorption,Remediation
更新于2025-09-23 15:23:52
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One step fabrication of dual optically/magnetically modulated walnut-like micromotor
摘要： In this paper, we report a novel multi-responsive walnut-like micromotor consisting of polycaprolactone (PCL), iron oxide nanoparticles (Fe3O4NPs) and catalase, which is constructed through a one-step electrospinning method. Based on the catalytic activity and photothermal and magnetic responsiveness originating from catalase and Fe3O4NPs, respectively, the resulting micromotor exhibits autonomous movement in the presence of hydrogen peroxide (H2O2) fuel, controlled motion velocity under light irradiation and guided movement direction upon the application of an external magnetic field. Owing to the hydrophobic nature of the PCL polymer constituent inside the micromotor, the autonomous moving micromotor can collect spilled oil inside a solution once it collides with the oil droplet. Since the micromotor could be separated out using a magnetic field, we believe the current walnut-like micromotor holds great promise in the field of environmental remediation.
关键词： one-step fabrication,micromotor,environmental remediation,motion control,multi-responsive
更新于2025-09-19 17:15:36
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A review on sustainable routes of synthesis and applications of Cuprous Oxide Nanoparticles and their Nanocomposites.
摘要： Nature acts like a “Bio-Laboratory” consisting of plants, algae, fungi, yeast etc. which are composed of bio-molecules. These naturally occurring bio-molecules play a vital role in the synthesis of Cuprous oxide (Cu2O) nanoparticles (NPs) and their nanocomposites (NCs) with distinct shapes and sizes, thereby acting as a driving force for designing safer, greener and sustainable routes using less hazardous chemicals. The present review focuses on the eco-friendly protocols for synthesis of Cu2O NPs and their NCs, characterisation techniques and various applications in organic catalysis, biosensing, environmental remediation and medicinal chemistry. The pivotal role of Cu2O NPs and their NCs in catalysing coupling reactions (C-C and C-N), multicomponent, oxidation-reduction and heterocyclic reactions have been higlighted. It emphasises its role in sustainability of the environment and its range of versatility in heterogenous catalysis. Furthermore, their use in biosensing (electrochemical detection) generates special interest in bioscience and clinical diagnosis. Their significance ensures to build a bridge between academic research and safety of the surroundings.
关键词： green chemistry,medicinal applications,biogenic synthesis,environmental remediation,biosensing,catalysis,Cuprous oxide nanoparticles
更新于2025-09-19 17:15:36
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Cyano-rich mesoporous carbon nitride nanospheres for visible-light-driven photocatalytic degradation of pollutants
摘要： Visible-light-responsive photocatalysis offers exciting opportunities for sustainable environmental pollution control, but the unsatisfactory photoactivity of the existing photocatalysts impedes their practical application. Here, we fabricated a high-activity mesoporous carbon nitride nanosphere (MCNS) photocatalyst by a hard template synthesis method through incomplete polycondensation of the cyanamide precursors during thermal polymerization. The MCNS showed a unique nanosphere structure with a larger specific surface area and possessed more abundant cyano groups than two other graphitic carbon nitride (g-C3N4) materials (i.e., nanosheet and bulk g-C3N4). Experimental results and theoretical calculations indicate important roles of the cyano groups in narrowing the catalyst band gap to favor visible light absorption and accelerating the separation of the electron–hole pairs. With such superior surface properties and improved charge separation efficiency, the MCNS exhibited 14.7 times higher photocatalytic activity for bisphenol A (BPA) degradation than the bulk g-C3N4. The MCNS also showed good stability during repeated use. Therefore, the as-prepared MCNS has great potential for visible-light-responsive photocatalysis in environmental remediation and other photocatalytic applications.
关键词： pollutant degradation,visible-light-driven photocatalysis,bisphenol A,environmental remediation,Cyano-rich mesoporous carbon nitride nanospheres
更新于2025-09-19 17:15:36
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Carbonaceous Biomass-Titania composites with Ti–O–C Bonding Bridge for Efficient Photocatalytic Reduction of Cr(VI) Under Narrow Visible Light
摘要： The aim of this study was to develop carbonaceous materials hybridized with anatase TiO2 composed of Activated Carbon-TiO2 (AC-TiO2), Olive Pits-TiO2 (OP-TiO2) and Wood Shaving-TiO2 (WS-TiO2) by ultrasonic-assisted sol-gel process for the photocatalytic Cr(VI) reduction under UV and narrow visible light. The morphology, crystal structure, surface chemistry and optical properties of the as-prepared and bare-TiO2 were investigated by SEM-EDS, XRD, FTIR, BET, UV-DRS, XPS and photo-current measurements. Unlike bare-TiO2, these composite photocatalysts exhibited an enhanced absorption in visible-light. The band gap energies were found to be 3.20 eV, 2.89 eV, 2.81 eV and 2.95 eV for bare-TiO2, AC-TiO2, OP-TiO2 and WS-TiO2, respectively. On the other hand, as-prepared photocatalysts showed significantly improved photocatalytic Cr(VI) reduction performances under UV and visible light illumination compared to bare-TiO2. A total reduction of 10 ppm of Cr(VI) was obtained after 30 min, 50 min and 130 min under visible light (>420) for AC-TiO2, OP-TiO2 and WS-TiO2, respectively at pH: 3 and in the presence of 10 ppm tartaric acid as hole scavenger, while no reduction was detected for bare-TiO2 under visible light (>420). The efficient photocatalytic reduction of Cr(VI) under visible light by AC-TiO2, OP-TiO2 and WS-TiO2 was mainly due to (i): the narrow band gap of TiO2 nanoparticle deposited in carbonaceous materials, (ii): self-photo-sensitizer role of carbonaceous materials via Ti–O–C bonds and (iii): the electron transfer from TiO2 to carbonaceous materials.
关键词： Cr(VI) Reduction,Environmental remediation.,Visible Light,Photocatalysis,Carbonaceous Biomass-TiO2,Band-gap Narrowing
更新于2025-09-19 17:15:36
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Fabrication of nanoheterostructures of boron doped ZnO-MoS2 with enhanced photostability and photocatalytic activity for environmental remediation applications
摘要： In this work, we have developed two dimensional (2D) nanosheets-nanoparticles (0D) nanoheterostructures of boron-doped ZnO nanoparticles loaded over MoS2 nanosheets with enhanced photocatalytic activity for pollutant removal. A series of nanoheterostructures with varying amount of MoS2 nanosheets were prepared using facile hydrothermal method and characterized by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) techniques to confirm there successful synthesis. The optimized nanoheterostructure photocatalyst with 1 wt% of MoS2 nanosheets (BZM1) exhibits superior photocatalytic activity for pollutant removal under visible light illumination. The superior photocatalytic activity of BZM1 nanoheterostructure has been supported by photoluminescence (PL) studies which show the remarkably decreased PL intensity signifying the low recombination rate of photogenerated charge carriers. In addition, the formation of 0D-2D heterojunction plays a significant role in enhancing the photocatalytic activity by accelerated photogenerated charge carriers separation in space and ultimately improved photocatalytic activity. Furthermore, the plausible photocatalytic mechanism has been discussed in detail on the basis of active species trapping experiment which validate the significant role of holes and hydroxyl radicals in degradation process. Overall, this work paves way for the facile fabrication of 0D-2D nanoheterostructures for diverse applications.
关键词： Boron doped ZnO,charge transfer,B-ZnO-MoS2 nanoheterostructures,environmental remediation,photocatalysis
更新于2025-09-19 17:15:36
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Pulsed light for a cleaner dyeing industry: Azo dye degradation by an advanced oxidation process driven by pulsed light
摘要： Water pollution by wastewater containing dyes is an environmental issue that can be mitigated by the use of advanced oxidation processes (AOP). Pulsed light (PL) is an emerging food processing technology that uses eco-friendly lamps and can potentially be adapted as light source of an UV-based AOP. In the present work, a PL/H2O2 process was tested for the decolourization of two azo dyes, and a pulsed light/H2O2/ferrioxalate process was tested for the decolourization of one azo dye. The efficiency of the PL/H2O2 process in a batch reactor under different parametric values: dye concentration, pH, H2O2 and salt doses was followed by spectrophotometry and fitted to first-order kinetics; and several degradation products were detected. In the PL/H2O2 process, decolourization rates increased at low dye concentrations and high H2O2 doses, were pH-dependent and were inhibited by the addition of NaCl, Na2SO3 or Na2CO3. More than 50 % decolouration was achieved with the PL/H2O2 process for both dyes after applying 54 J/cm2 (25 light pulses). The PL/H2O2/ferrioxalate process achieved > 95 % decolouration for Methyl orange when applying 21 J/cm2 (10 pulses); that level of energy can be supplied by PL commercial systems in nine and four seconds respectively. No known toxic degradation products were detected. Results show that a PL/H2O2 process has potential to be used for the efficient degradation of dyes from wastewater. Furthermore, the efficacy of this process can be improved by the use of ferrioxalate. PL technology could become an alternative light source to contribute to decrease the environmental impact of wastewater produced by the dyeing industry.
关键词： pulsed light,ferrioxalate,advanced oxidation process,azo dye,wastewater remediation
更新于2025-09-19 17:15:36
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Recent advances in carbon quantum dot (CQD)-based two dimensional materials for photocatalytic applications
摘要： CQDs are a new class of carbon material with ultrafine sizes and readily tunable optical properties, which make them extremely intriguing. CQDs have gained widespread attention due to their potential and versatility, and they can be applied in many different fields. One of their many applications is photocatalysis, which has garnered incessant research interest in recent years. State-of-the-art technology utilizes sustainable solar energy, which is both clean and virtually inexhaustible. To date, the photocatalytic performance of CQDs in their raw form is still far from ideal. Nevertheless, they can be substantially enhanced through several modification techniques. In this review, strategies to improve the photocatalytic performance of CQDs, such as size-tuning, surface passivation and functionalization, and elemental doping, are extensively discussed. The review also covers the latest advances in the use of CQDs in photocatalysis to address both environmental and energy-related issues. Particular emphasis is placed on the formation of 0D/2D heterojunction nanocomposites with several 2D materials, such as graphene, graphitic carbon nitride, metal oxides and metallates, metal oxyhalides, transition metal oxides and chalcogenides. The hybridization routes to binary nanocomposites, and their photocatalytic application to carbon dioxide reduction, hydrogen production, and dye and pollutant degradation, are thoroughly reviewed in this paper.
关键词： Two-dimensional materials,Photocatalysis,Energy generation,Carbon quantum dots,Environmental remediation,Heterojunction nanocomposites
更新于2025-09-16 10:30:52
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Laser synthesis of magnetite-partially reduced graphene oxide nanocomposites for arsenate removal from water
摘要： Herein, we report the development of a facile process for the synthesis of magnetite-partially reduced graphene oxide (Mag-PRGO) without the use of chemical reducing agents or solvents for the efficient removal of arsenate As(V) ions from contaminated water. The Mag-PRGO is synthesized using the laser vaporization-controlled condensation method where a compressed target consisting of metallic iron (Fe) powder and solid graphene oxide (GO) is laser vaporized in an O2–He atmosphere resulting in the simultaneous oxidation of the Fe nanoparticles and the partial reduction of the GO to form the Mag-PRGO nanocomposite where the magnetic Fe3O4 nanoparticles are anchored to the surface of the PRGO nanosheets. FTIR, Raman, XPS, XRD, TEM, and SEM confirm the successful attachment of the magnetic Fe3O4 nanoparticles to the PRGO nanosheets. The Mag-PRGO (50 wt% Fe) adsorbent shows exceptional selectivity for the extraction of As(V) ions with a capacity of 132 mg/g with no leaching of Fe ions into the solution, placing it among the best carbon-based materials for the efficient removal of As(V) from aqueous solutions. The Mag-PRGO displays a 100% removal of As(V) at concentrations up to 100 ppm with 98% and 100% removal within 15 min and 30 min, respectively, at 50 ppm concentration. The excellent agreement of the experimental sorption isotherms with the Langmuir model suggests a monolayer adsorption behavior. The mechanism of As(V) removal is based on surface complexation between the protonated hydroxyl groups on the surface of Mag-PRGO and the monobasic and dibasic arsenate anions forming (Fe–O–As) bonds as confirmed by FTIR and XPS. The Mag-PRGO is easily regenerated with the desorption of the As(V) ions reaching 99% from their maximum sorption capacities using NaOH. The efficient magnetic separation and high chemical stability of Mag-PRGO are demonstrated over six adsorption–desorption cycles of As(V). The Mag-PRGO is proposed as an excellent remediation adsorbent for the extraction of As(V) from contaminated water.
关键词： Magnetite-partially reduced graphene oxide,Arsenate removal,Water remediation,Adsorption,Laser vaporization-controlled condensation
更新于2025-09-16 10:30:52