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.
Deepti R. Kulkarni; Narasimha H. Ayachit; Raviraj M. Kulkarni
Abstract
We report an inexpensive TiO2 based quantum dot solar cell (QDSSC) with improved power conversion efficiency prepared by simple techniques. Barium doped zinc sulfide has been successfully deposited on cadmium sulfide quantum dots (QDs) by simple successive ion layer adsorption and reaction (SILAR) technique. ...
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We report an inexpensive TiO2 based quantum dot solar cell (QDSSC) with improved power conversion efficiency prepared by simple techniques. Barium doped zinc sulfide has been successfully deposited on cadmium sulfide quantum dots (QDs) by simple successive ion layer adsorption and reaction (SILAR) technique. The Barium doped zinc sulfide is utilized as a passivation layer in the QDSSC, which helped in better charge separation. The copper sulfide (Cu2S) and reduced graphene oxide deposited on FTO was used as a counter electrode. The developed QDSSC showed superior performance when tested with AM 1.5 solar simulator using sulfide/Polysulfide electrolyte. The photoconversion efficiency of FTO/TiO2/CdS/BaZnS/Cu2S-Graphene oxide is better than that of FTO/TiO2 /CdS/ZnS/Cu2S-Reduced Graphene oxide. Copyright © 2018 VBRI Press.
Rabesh Kumar Singh; Anuj Kumar Sharma; Amit Rai Dixit; Arun Kumar Tiwari; Amitava Mandal
Abstract
Health and environmental concerns about the use of excessive conventional cutting fluids during conventional machining has led to the development of a new type of cutting fluid. Inefficient disposal of industrial cutting fluids during wet machining also reduces the use of conventional cutting fluid. ...
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Health and environmental concerns about the use of excessive conventional cutting fluids during conventional machining has led to the development of a new type of cutting fluid. Inefficient disposal of industrial cutting fluids during wet machining also reduces the use of conventional cutting fluid. Nano-material mixed cutting fluids have shown superior thermal properties and tribological properties. In the present work, different nanofluids are prepared by suspension of Titanium dioxide (TiO2), Silicon oxide (SiO2) and Aluminum oxide (Al2O3) nanoparticles in vegetable oil and water-based emulsion at room temperature in different volumetric concentrations. The viscosity and density of the developed nanofluids are measured at different temperatures for different nanoparticle volumetric concentrations. From the experimental results, it has been found that with the increase of nanoparticle concentration in base fluid, enhanced the its viscosity and density. Furthermore, addition of nanoparticles at 25 ºC enhances viscosity more compared to its addition at higher temperatures. For an increase of concentration from 0.25% to 3%, enhancement in viscosity of Al2O3, SiO2 and TiO2 nanofluids is observed as 41.6%, 43.75% and 35.55%, respectively, while for higher temperatures almost constant improvement of 25%, 24% and 30% is observed for Al2O3, SiO2 and TiO2 nanofluids, respectively. The viscosity and density of three different nanofluids are also compared. Results showed that newly prepared Al2O3 based nanofluid exhibits better properties than TiO2 and SiO2 based nanofluids. 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.
J. Dhanalakshmi; D. Pathinettam Padiyan
Abstract
GdxTi1-xO2 nanocomposites with x=0.00, 0.02, 0.04, 0.06, 0.08 & 0.10 were prepared through sol-gel method. The samples were characterized using X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), High resolution scanning electron microscope (HR-SEM), Raman spectroscopy and photoluminescence ...
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GdxTi1-xO2 nanocomposites with x=0.00, 0.02, 0.04, 0.06, 0.08 & 0.10 were prepared through sol-gel method. The samples were characterized using X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), High resolution scanning electron microscope (HR-SEM), Raman spectroscopy and photoluminescence spectroscopy (PL). The XRD pattern and Raman spectra confirmed the presence of crystalline nature and phase pure anatase tetragonal system. The average crystallite size of the samples was between 10 to 18 nm. HR-SEM images indicated the formation of spherical like particles of GdxTi1-xO2 nanocomposites. An obvious reduction in particle size of GdxTi1-xO2 nanocomposites were noticed while comparing the SEM images of bare TiO2 and composite samples. Coupling of Gd is responsible for slight blue shift in absorption edge. The presence of oxygen vacancies is confirmed in Raman and PL spectra. These oxygen vacancies potentially trap electrons and restrict the electron-hole recombination and thus improve the photocatalytic reactions.
