M. Prathap Kumar; G.A. Suganya Josephine; A. Sivasamy
Abstract
Exploration of semiconductors in the field of photocatalysis plays a crucial role in energy and environmental remediation in particular oxidation/reduction of toxic organic contaminants from water and wastewater. The present research work aims on synthesis of pristine CeO2nanoparticles by precipitation ...
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Exploration of semiconductors in the field of photocatalysis plays a crucial role in energy and environmental remediation in particular oxidation/reduction of toxic organic contaminants from water and wastewater. The present research work aims on synthesis of pristine CeO2nanoparticles by precipitation method and was thoroughly characterized by Fourier Transform Infrared spectroscopy, X-ray Diffraction, UV-vis-Diffuse Reflectance Spectroscopy, High Resolution Scanning Electron Microscopy, EDAX and Electron Spin Resonance techniques. The band gap energy (Ebg) was found to be 3.19 eV. The synthesized nanomaterials showed spherical morphology and the particles size ranged from 50-93 nm. The insitu generation of ·OH radicals was confirmed from ESR studies. The synthesized CeO2nanospheres was evaluatedin photocatalytic oxidation of an azo dye Acid orange 10 under Ultraviolet and visible light irradiations. Experimental studies such as pH, catalyst amount and effect of initial dye concentration were also studied. Kinetic studies indicate the photo reaction follows pseudo-first order rate equation. The photocatalytic oxidation of dye molecules were monitored by UV-visible spectroscopy and COD analyses. The level of chemical oxygen demand (COD) of the photodegraded samples decreases in both the photocatalytic systems indicating that dye molecules readily degraded under present experimental conditions.Effect of electrolytes like MgSO4,KCl, Na2CO3 and NaHCO3 were also investigated to check interference of inorganic anions on photocatalytic oxidation of dye molecules using CeO2 nanospheres. Finally, the prepared catalyst was checked for its reusability and the photocatalyst exhibited better photocatalytic activity evenafter three cycles of regeneration.Copyright © VBRI Press.
G.A. Suganya Josephine; K. Jayaprakash; A. Sivasamy
Abstract
Heterogeneous semiconductor nanomaterials are widely employed nowadays as efficient photocatalysts for selective organic transformation reactions. A co-precipitation technique was employed for the preparation of ZnO doped dysprosium oxide from the respectivemetal nitrates and characterization studies ...
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Heterogeneous semiconductor nanomaterials are widely employed nowadays as efficient photocatalysts for selective organic transformation reactions. A co-precipitation technique was employed for the preparation of ZnO doped dysprosium oxide from the respectivemetal nitrates and characterization studies were conductedby FT-IR, X-Ray Differaction, UV-Visible-DRS and FE-SEM analysis. XRD showed the prepared nanomaterial to be in a nano range with high crystallinity. The particles possesed a spherical morphology and of the order of 40-50 nm(particle size) as evidenced from FE-SEM analysis. From theUV-Visible-DRS analysis the band gap energy was calculated as 3.15 eV. The synthesizedZnO doped dysprosium oxide was employed as a photocatalyst under UV light irradiation for selective organic transformation reaction. Quinones especially benzoquinones are a class of compounds which forms a basic structural skeleton for various natural compounds. They are widely employed asa precursor for natural products synthesis. Herein we report the synthesis of N-phenyl-p-benzoquinonimine from diphenylamine by employing ZnO doped dysprosium oxide as a photocatalyst under UV light irradiation in ethanol. Thin Layer Chromatography was used to check the progress of the reaction. Optimization studies for the reaction parameters were conducted systematically.
Dinesh Selvakumaran; Anandan Manickam; Gopalakrishnan Ravi; Gohulkumar Muthusamy; Barathan Seshatri
Abstract
Highly crystalline Mg2SnO4 nanocubes were successfully synthesized using a facile hydrothermal method. Further activated carbon was loaded with Mg2SnO4 nanoparticles in order to enhance the photocatalytic performance. Photocatalytic performance of Mg2SnO4 nanocubes and activated carbon loaded Mg2SnO4 ...
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Highly crystalline Mg2SnO4 nanocubes were successfully synthesized using a facile hydrothermal method. Further activated carbon was loaded with Mg2SnO4 nanoparticles in order to enhance the photocatalytic performance. Photocatalytic performance of Mg2SnO4 nanocubes and activated carbon loaded Mg2SnO4 nanocomposites were examined by methyl green and methylene blue dye degradation under the exposure of UV light. However, results suggest that activated carbon loaded Mg2SnO4 nanocomposites has significantly enhanced the photocatalytic performance over Mg2SnO4 nanocubes. It is assumed that better photocatalytic activity is caused by the higher specific surface area of activated carbon loaded Mg2SnO4 nanocomposites. Furthermore, cyclic voltammetry was used to analyze the electrochemical properties of the samples. Results indicate that activated carbon significantly enhanced the electrochemical properties of Mg2SnO4 nanoparticles. Copyright © VBRI Press.
Raviraj M. Kulkarni; Ramesh S. Malladi; Manjunath S. Hanagadakar
Abstract
Photocatalytic degradation of textile dye derivative Methyl Orange (M.O) has been studied in aqueous medium using 2% copper doped zinc oxide (2% Cu-ZnO) nanoparticles under UV irradiation. Simple inexpensive chemical precipitation method was used for synthesis of pure and copper doped zinc oxide nanoparticles. ...
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Photocatalytic degradation of textile dye derivative Methyl Orange (M.O) has been studied in aqueous medium using 2% copper doped zinc oxide (2% Cu-ZnO) nanoparticles under UV irradiation. Simple inexpensive chemical precipitation method was used for synthesis of pure and copper doped zinc oxide nanoparticles. The prepared nanoparticles pure and copper doped zinc oxide was characterized by X-ray Diffraction Technique (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis. The prepared nanoparticles were hexagonal wurzite structure. Photocatalytic efficiency of 2% Cu-ZnO were evaluated by studying mineralization of methyl orange (M.O.) as a model compound. The M.O. kinetics degradation was investigated under different parameters such as pH of the medium, catalyst dosage, M.O concentration, intensity of light etc. In addition reusability aspects of nanoparticles where also studied, which reveals that reused nanoparticles exhibited same results as that of virgin particles. Copyright © 2018 VBRI Press.
Raviraj M. Kulkarni; Ramesh S. Malladi; Manjunath S. Hanagadakar
Abstract
Liquid Impregnation (LI) technique was developed to prepare 1% and 2% Ag doped Titania nanoparticles. The characterization of the prepared nanoparticles was achieved by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and Transmission Electron Microscopy ...
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Liquid Impregnation (LI) technique was developed to prepare 1% and 2% Ag doped Titania nanoparticles. The characterization of the prepared nanoparticles was achieved by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and Transmission Electron Microscopy (TEM). The crystallite size was obtained by Scherrer equation analysis of XRD main peak of doped and undoped nanoparticles. It was observed that crystallite size of bare TiO2 was 17.00 nm, whilst the crystallite size of 1% Ag doped titania and 2% Ag doped titania was 13.07 nm to 14.17 nm. TEM images ascertained that particle size of Ag-TiO2 nanoparticles were in the range 40-45 nm in length and 10-15 nm in width. The pH of the solution exerted a negative effect on photodegradation rate of sparfloxacin. The masking effect on the degradation of sparfloxacin was observed at higher catalyst dosages. The increase in UV intensity linearly enhanced the degradation rate of sparfloxacin and the influence of initial sparfloxacin concentration on the degradation rate was investigated and discussed. Copyright © 2018 VBRI Press.
Tarek S. Jamil; Eman S. Mansor
Abstract
A heterojunctionBiOI0.5Br0.5 was prepared for enhancing the photocatalytic performance of BiOX (X= Br or I) by facile method at room temperature using Bismuth Nitrate Bi(NO3)3.5H2O as Bismuth source. All prepared materials were fully identified by the required characteristics. The effect of heterojunction ...
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A heterojunctionBiOI0.5Br0.5 was prepared for enhancing the photocatalytic performance of BiOX (X= Br or I) by facile method at room temperature using Bismuth Nitrate Bi(NO3)3.5H2O as Bismuth source. All prepared materials were fully identified by the required characteristics. The effect of heterojunction as well as BiOBr and BiOI on the photocatalytic activities were studied through degradation of widely used endocrine disturbing compound, Bisphenol – A, in aqueous solution under commercial visible lamp. The percent removal of Bisphenol– A was 55%, 79% and 93% with BiOBr, BiOI and BiOI0.5Br0.5 respectively after 120 min irradiation time using 1.0 g/L dose of photocatalysts and pH10. Accordingly, heterostructure considered a promising method that can be used to enhance pure photocatalyst for degradation of organic pollutants in water. Copyright © 2018 VBRI Press.
Bhishma Karki; Jeevan Jyoti Nakarmi; Rhiddi Bir singh; Manish Banerjee
Abstract
The influence of Au doping in ZnO thin films was studied with respect to photoelectrocatalytic degradation of methylene blue (MB). Influence of Au doping concentration onto PEC structural morphological, optical and luminescence properties of the ZnO thin films were thoroughly investigated. The maximum ...
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The influence of Au doping in ZnO thin films was studied with respect to photoelectrocatalytic degradation of methylene blue (MB). Influence of Au doping concentration onto PEC structural morphological, optical and luminescence properties of the ZnO thin films were thoroughly investigated. The maximum value of Isc and Voc for 3 at. % Au:ZnO thin films confirms the optimization of doping percentage. XRD and SEM were used to study the structure and morphology of the films. Films were nanocrystalline and exhibit a hexagonal crystal structure with no additional phases of gold compounds. For degradation of MB, Au:ZnO films were used as photoelectrode, it was observed that due to Au:ZnO 80% degradation of MB occurs in 150 min. Moreover, large area (100 cm2) Au doped ZnO thin films have been prepared on FTO coated glasses (10–15 Ω). Photocorrosion of ZnO electrode was examined by atomic absorption spectroscopy and no zinc was observed in AAS measurement. Copyright © 2017 VBRI Press.
Gurpreet Kaur; Bikramjeet Singh; Paviter Singh; Manpreet Kaur; Anup Thakur; Manjeet Kumar; Rajni Bala; Akshay Kumar
Abstract
Nontoxic and earth abundant nanostructured semiconductors have experienced wide attention of researchers recently. One of the more studied material is Iron pyrite (FeS2) owing many different promising applications. Herein, the synthesis of nanostructures by varying the reactant precursors of iron and ...
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Nontoxic and earth abundant nanostructured semiconductors have experienced wide attention of researchers recently. One of the more studied material is Iron pyrite (FeS2) owing many different promising applications. Herein, the synthesis of nanostructures by varying the reactant precursors of iron and sulphur has been reported. The molar ratio of iron and sulphur precursors play a crucial role in determining the quality of nanostructures. This work further advances synthesis with pyrite purity, structure control and then promotes use in photovoltaics, photocatalysis and photoelectrochemistry applications. Copyright © 2017 VBRI Press.
Yuvraj S. Malghe; Atul B. Lavand
Abstract
Here, we report on microemulsion synthesis of nitrogen (N) doped TiO2 quantum dots (QDs) with improved visible-light response. XRD, FTIR, XPS, EDX and Raman spectroscopy confirms that N was doped successfully in TiO2 lattice. SEM and TEM study confirms spherical morphology of N-doped TiO2 QDs. N-doped ...
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Here, we report on microemulsion synthesis of nitrogen (N) doped TiO2 quantum dots (QDs) with improved visible-light response. XRD, FTIR, XPS, EDX and Raman spectroscopy confirms that N was doped successfully in TiO2 lattice. SEM and TEM study confirms spherical morphology of N-doped TiO2 QDs. N-doped TiO2 sample exhibit a narrower band gap and stronger visible light absorption as compared to pure TiO2. The assistance of the N enhances the photocatalytic activity in the visible light region by promoting the separation of the photo generated electrons and holes to accelerate the transmission of photocurrent carrier. Photocatalytic activity study evaluated for the degradation of acifluorfen herbicide under visible-light irradiation, demonstrated that N-doped TiO2 sample is more active than pure and commercial TiO2. The high visible-light photocatalytic activity is attributed to the anatase crystalline phase, small crystallite size, strong visible light absorption capacity and superior electron-hole charge carrier’s separation efficiency. The photoluminescence (PL) study was employed to test hydroxyl (•OH) radicals, which show that N-doped TiO2 helps to produce •OH radicals and favors to enhance its photocatalytic activity. N doped TiO2 quantum dots prepared in this work exhibit better photocatalytic activity and hence having a potential to use as a photocatalyst for the degradation of harmful organic chemicals, dyes and drugs coming out from industries and will help to keep environment clean and safe. Copyright © 2016 VBRI Press.
