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Nano Structured Ni and Ru Impregnated TiO <sub/>2</sub> Photocatalysts: Synthesis, Characterization and Photocatalytic Degradation of Neonicotinoid Insecticides
摘要： Titania by sol gel and Ni–Ru titania catalysts by wet impregnation methods were prepared and characterized by XRD, UV-DRS, BET and TEM techniques. Catalytic activities of the photocatalysts were evaluated towards the degradation of three widely used neonicotinoids type insecticides namely acetamiprid, imidacloprid and thiamethoxam under UV, Visible and solar irradiations. The reaction parameters such as initial concentration of the insecticide, weight of the catalyst and pH of the system were found to influence the reaction rate. The results indicated that the metal impregnated catalysts were found to be more active than pure TiO2. Ni/TiO2 or Ru/TiO2 catalysts degraded all the insecticides completely even under visible irradiation. The observed visible activity of the catalysts was attributed to their lower band gap values. HPLC and TOC analyses revealed that mineralisation of the insecticides occurred through dearomatization by multiple hydroxylation and oxidation. The degradation pathway and the kinetics were also discussed in detail.
关键词： HPLC,Photocatalysis,Sol–Gel Method,Titania,Neonicotinoids,Insecticides
更新于2025-09-04 15:30:14
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Preparation of Nano Spinel Doped TiO <sub/>2</sub> and Its Photocatalytic Activity Evaluation Under Visible Light Irradiation
摘要： Nano MgFe–TiO2 photocatalyst was prepared by mixing nanoscale spinel compounds such as magnesium ferrite (MgFe) and TiO2. The cations produced by MgFe are affected by various influencing factors such as calcination temperature, precursor, and mass ratio of Mg and Fe. This study is to evaluate the photocatalytic efficiency of nano MgFe-doped TiO2 under visible light according to the composition ratio of Mg, Fe and TiO2. With an increase the percentage of doping (i.e., Mg and Fe) over TiO2, the band gap between conduction band and valance band decreases, therefore showing better photocatalytic activity in visible light. Also as percentage of doping over TiO2 increases, surface area of the catalyst also increases subsequently resulting in an increase in the adsorption capacity.
关键词： Visible Light,Spinel Compound,Magnesium Ferrite,Photocatalysis,TiO2
更新于2025-09-04 15:30:14
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Preparation, Characterization, and Photocatalytic Activity of LaMnO3 Nanorods-reduced Graphene Oxide Composite
摘要： Background: A new type of photocatalyst with a perovskite structure is recently utilized. The one-dimensional nanostructure of photocatalysts holds great charge mobility along the crystal longitudinal dimension and can hence provide the direct pathways of charge carriers. Graphene holds a superior electrical conductivity and high specific surface area. The aims of this paper are to make LaMnO3 nanorods disperse on the graphene surface. The synergistic effect between graphene and LaMnO3 nanorods enhances the photocatalytic performance. Method: LaMnO3 nanorods–graphene is fabricated using cetyltrimethyl ammonium bromide as template by a simple hydrothermal reaction followed by heat treatment. Results: XRD result indicates that the appropriate calcination temperature for the perovskite structure formation is 650°C. Electron microscopy reveals the LaMnO3 nanorods exhibit a good dispersion behavior on the surface of graphene and the specific surface area of LaMnO3 nanorods-graphene is higher than that of LaMnO3 nanorods. The activities of LaMnO3 nanorods–graphene and TiO2 are compared for degradation of Direct Green BE, the decolorizing rates are 99.93% and 79.45%, respectively. Conclusion: The photocatalytic results for Direct Green BE degradation showed that LaMnO3 nanorods–reduced graphene oxide exhibit a superior photocatalytic performance than that of LaMnO3 nanorods and TiO2 powders. The one-dimensional nanorod structure of LaMnO3 can provide a direct pathway for electronic transmission, and the increased aspect ratio is favorable for reducing the recombination probability of the electron and hole. Meanwhile, the photoelectron transport along the graphene sheets can promote the separation of the e?–h+ pairs.
关键词： Perovskite,nanorods,hydrothermal reaction,composite,photocatalysis,graphene
更新于2025-09-04 15:30:14
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Large Scale Synthesis of ZnO Nanostructures of Different Morphologies through Solvent-free Mechanochemical Synthesis and their Application in Photocatalytic Dye Degradation
摘要： Well crystalline, near-stoichiometric zinc oxide nanostructures of different morphologies are fabricated in large scale, utilizing a simple, cost effective mechanochemical synthesis in absence of solvent. Effects of ionic and nonionic surfactants along with the concentration of hydrolyzing agent on the evolution of nanostructure morphology have been studied. It has been observed that while a cationic surfactant such as Cetyltrimethylammonium Bromide (CTAB) favors the nanostructures to growth along their polar c-axis, a nonionic surfactant such as Polyvinylpyrrolidone (PVP) reduces their preferred c-axis growth. Increase of hydrolyzing agent in the reaction mixture enhances the growth rate of the nanostructures. The nanostructures have been tested for photodegradation of anionic dye molecules such as Methylene Blue (MB). All the nanostructures manifest high photocatalytic performance. Apart from morphology, the specific surface area, crystal plane orientation and the concentration of basic sites at surface are seen to contribute significantly to the photocatalytic performance of the zinc oxide nanostructures.
关键词： Mechanochemical Synthesis,Photocatalysis,Nanostructures,ZnO,Dye Degradation
更新于2025-09-04 15:30:14
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A Facile Method for Preparation of Cu2O-TiO2 NTA Heterojunction with Visible-Photocatalytic Activity
摘要： Based on highly ordered TiO2 nanotube arrays (NTAs), we successfully fabricated the Cu2O-TiO2 NTA heterojunction by a simple thermal decomposition process for the first time. The anodic TiO2 NTAs were functioned as both “nano-container” and “nano-reactors” to load and synthesize the narrow band Cu2O nanoparticles. The loaded Cu2O expanded absorption spectrum of the TiO2 NTAs from ultraviolent range to visible light range. We found that the Cu2O-TiO2 NTA heterojunction films had visible activity towards photocatalytic degrading methyl orange (MO). The photocatalytic abilities of the Cu2O-TiO2 NTA heterojunction films were found increased with the Cu2O content from 0.05 to 0.3 mol/L. This could be explained by more electron-hole pairs generated and less recombination, when the Cu2O-TiO2 heterojunction got formed. Here, we put forward this promising method, hoping it can facilitate the mass production and applications of Cu2O-TiO2 NTA heterojunction.
关键词： TiO2 nanotube,Visible photocatalysis,Thermal decomposition,Cu2O,Heterojunction
更新于2025-09-04 15:30:14
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Exfoliated $$\hbox {WS}_{2}$$WS2 nanosheets: optical, photocatalytic and nitrogen-adsorption/desorption characteristics
摘要： In this work, we report on structural, optical, photocatalytic and nitrogen adsorption–desorption characteristics of WS2 nanosheets developed via a hydrothermal route. X-ray diffraction (XRD) studies have revealed a hexagonal crystal structure, whereas nanodimensional sheets are apparently observed in scanning and transmission electron microscopy (SEM and TEM) micrographs. As compared to the bulk counterpart, the WS2 nanosheets exhibited a clear blue shift. Through Brunauer–Emmett–Teller (BET) surface area analysis, average surface area, pore volume and pore size of the NSs were calculated as 211.5 m2 g?1, 0.433 cc g?1 and 3.8 nm, respectively. The photocatalytic activity of the WS2 nanosheets was also examined with malachite green (MG) as the target dye under both UV and day light (visible) illumination conditions. Accordingly, a degradation ef?ciency as high as 67.4 and 86.6% were witnessed for an irradiation time duration of 60 min. The nano-WS2 systems have immense potential in optoelectronics, solid-lubrication and other next generation elements.
关键词： sorption process,photocatalysis,TMDC,Nanosheets
更新于2025-09-04 15:30:14
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Nanohybrid and Nanoporous Materials for Aquatic Pollution Control || Nanohybrid Photocatalysts for Heavy Metal Pollutant Control
摘要： In this decade, the environmental problem, especially for the wastewater treatment issue, has become a widespread concern. In the meantime, heavy metal pollutants have also caused great attention owing to their recalcitrance persistence and the large discharge scale into the environment. Heavy metal is defined as the element with the atomic weights between 63.5 and 200.6. In our environment, some hazardous heavy metals such as chromium (Cr), mercury (Hg), arsenic (As), lead (Pb), copper (Cu), nickel (Ni), etc. exist in the surface fresh water. Heavy metals tend to accumulate in the organism via the food chain and caused serious harm to the organism. Therefore, it is urgent for the worldwide researchers to find effective treatment strategies to remove heavy metal from wastewater.
关键词： Environmental Remediation,Photocatalysis,Wastewater Treatment,Nanohybrid Photocatalysts,Heavy Metal Pollutant Control
更新于2025-09-04 15:30:14
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Salicylic acid complexed with TiO2 for visible light-driven selective oxidation of amines into imines with air
摘要： The interplay of salicylic acid (SA) and reactive oxygen species (ROS) can modulate biotic and abiotic stress of plants, essential biological aerobic oxidation processes. Meanwhile, ROS plays a critical role in TiO2 photocatalytic system for the degradation of organic species. Herein, we developed a system consisted of SA and TiO2 aiming at the selective oxidation of organic molecules by ROS. Interestingly, SA complexed with TiO2 leads to ligand-to-metal charge transfer (LMCT) under visible light irradiation. The charge transfer from ligand (chemically adsorbed SA) to metal (conduction band of TiO2) activates O2 to ROS, superoxide (O2?). The positive charge located at ligand SA is connected with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) catalysis for direct two-electron oxidation of amines and later regenerated by O2. SA and its derivatives were screened as ligands of TiO2 for the selective aerobic oxidation of amines into imines under blue light-emitting diode (LED) irradiation in which 5-CH3O-SA (5-methoxysalicylic acid, 0.8 mol%) complexed with anatase TiO2 and coupled with TEMPO (5 mol%) confers significantly better results than the others. By this visible light LMCT route, both primary amines and secondary amines can be selectively oxidized into corresponding imines with atmosphere O2 as the terminal oxidant. Importantly, the desired product of N-benzylidenebenzylamine can be isolated in 92% yield.
关键词： Salicylic acid,Titanium dioxide,Amines,Photocatalysis,Surface complex
更新于2025-09-04 15:30:14
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Minireview: Selective production of hydrogen peroxide as a clean oxidant over structurally tailored carbon nitride photocatalysts
摘要： Hydrogen peroxide (H2O2) is a clean oxidant, and its demand has continuously risen in various industries for pulp/paper bleaching, chemical synthesis, wastewater treatment, etc. H2O2 is commercially produced by the anthraquinone method, which has some drawbacks, including (i) toxic solvent, (ii) explosive hydrogen gas as a precursor, and (iii) a high energy input; therefore, a new technology based on cost-effective and green processes is required. Photocatalytic production of H2O2 can be considered the most environmentally benign and economically feasible process because it requires only dissolved oxygen, water, and sunlight. Among various photocatalysts, polymeric carbon nitride (C3N4) is a promising candidate for H2O2 production by virtue of its (i) simple synthesis by a thermal polymerization, (ii) structure consisting of earth-abundant carbon and nitrogen, (iii) effective bandgap size for visible light absorption, and (iv) suitable position of conduction band for reduction of oxygen dissolved in water. In this minireview, the mechanism of H2O2 formation over C3N4 has been discussed, and the strategies to optimize the photocatalytic activity have been summarized regarding structural and surface modification techniques. This overview of diverse methodologies to selectively control electron transfer to dissolved oxygen should be in demand not only for developing new-generation C3N4-based materials, but also for commercialization of solar-light-driven photocatalytic H2O2 production system.
关键词： Hydrogen peroxide,structural modification,Photocatalysis,Carbon nitride,hybridization
更新于2025-09-04 15:30:14
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Fabrication of Heterogeneous Photocatalysts for Insight role of Carbon Nanofibre in Hierarchical WO3/ MoSe2 composite for Enhanced Photocatalytic Hydrogen Generation
摘要： Mimicking the natural photosynthesis system, artificial photocatalysis facilitates effective utilization of solar energy for environmental sustainability and hydrogen energy production. In this work, the robust and efficient carbon fiber has been successfully incorporated into the interface between WO3 nanodots and MoSe2 needles using the facile hydrothermal and solvothermal method. The suitable interfacial contact of heterogeneous photocatalysts plays a significant role in the separation/transfer of interfacial photogenerated electron-hole pairs and hetero-junction. It seems an efficient approach for enhanced photocatalytic performance since the greater area of contact could improve the interfacial rate of charge transfer. The phase structure of prepared WO3 nanodots changed from the monoclinic to hexagonal phase by the addition of co-catalyst. The experimental results exhibited that carbon fiber played a tri-functional role to boost up the photocatalytic activity over MoSe2 nanostructures. It’s not only act as operative co-catalyst but could also serve as the conductive electron bridges, rather than general cocatalyst, to accumulate electrons and encourage the hydrogen generation kinetics over the WO3 photocatalysts. More interestingly, the WO3-1% MoSe2-1.5% carbon fiber and WO3-1%MoSe2 nanocomposites demonstrated the excellent rates of hydrogen evolution 438.7 and 356.2 mmol/g.h, which were 7.6 and 6.17 times higher when compared to that of pure MoSe2, respectively. Under the visible light excitation, the atomically junction encourages fast electron transfer from nanofibers to MoSe2 to suppress the rapid recombination kinetics within WO3 nanodots and extend the lifetime of WO3 charge carrier’s, thereby releasing more photogenerated electrons with higher reducing power for hydrogen evolution. The current work can contribute with new perspectives and mechanistic insight for the design and development of heterogeneous photocatalysts WO3 based nanostructures using the combination of MoSe2 and trifunctional carbon nanofibers for environment and energy harvesting applications.
关键词： Sustainable Environment,Hydrogen Evolution,Carbon nanofibers,Photocatalysis,Nanostructures
更新于2025-09-04 15:30:14