ANNEALING EFFECT ON OPTICAL PROPERTIES OF WO3 NANOSTRUCTURES

Author (s) : Mrs.A.PARVEEN

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Abstract :
Tungsten trioxide nanoparticles were synthesized using sodium tungstate as precursor and sodium chloride (Na₂WO₄.2H₂O), in the presence of HCl by cost-effective and single step hydrothermal method (HT) and annealed at 200⁰C, 400⁰C, 600⁰C, 800⁰C and 1000⁰C. These prepared samples were characterized by X-Ray diffraction, Fourier Transform, Infrared Spectroscopy, Scanning Electron Microscopy, UV-Visible, Photoluminescence and Raman Spectroscopy and photo catalysis techniques. From the XRD pattern the structure was confirmed using FTIR analysis. From the optical absorption spectra the band gap was calculated the range of 2.98eV – 3.16eV for as prepared and annealed at 1000⁰C. Photoluminescence (PL) Spectra showed deep level (DL) emission due to oxygen vacancies. Raman analysis of chemical structure of WO3 nanoparticles. The transverse optic (TO) and longitudinal optic (LO) modes were observed at 711.5cm^-1 and 805 cm^-1 respectively for as prepared and annealed at 2000⁰C of WO₃ nanoparticles. The intensity of these modes increased with increasing the annealing temperature to 1000⁰C and also shows shift towards higher wave number side. The degradation efficiency was calculated as 45%, 53%, 65%, 70%, 80% and 87% for as prepared, annealed at 200⁰C, 400⁰C, 600⁰C, 800⁰C and 1000⁰C of WO³ nanoparticles respectively. The sample annealed at 1000⁰C shows high degradation efficiency compared to other samples.

Keywords : Photo catalysis techniques.

Conference Date : 30/08/2019

Pages : 107

Paper ID : 19105