SYNTHESIS OF SILVER (Ag) DOPED ZINC OXIDE (ZnO) NANOPARTICLES AS EFFICIENTPHOTOCATALYTIC ACTIVITY FOR DEGRADATION METHYLENE BLUE DYE

Abstract

Zinc oxide (ZnO) and silver doped zinc oxide (Ag-ZnO) nanoparticles were prepared using zinc nitrates as oxidizers, glycine and citric acid as fuels as solution combustion synthesis (SCS) at 500°C. X-ray diffraction (XRD) pattern demonstrates the presence of Ag+ in the hexagonal zincite structure of ZnO. The average crystalline size of the particles of ZnO and Ag-ZnO were found to 47 nm and 74 nm respectively. From the Fourier transform infrared (FTIR) spectrum, the composition of Ag doped ZnO confirmed Ag-Zn-O stretching vibration at 510 cm-1. The UV-Visible absorption spectra results showed that synthesized ZnO and Ag-ZnO nanoparticles exhibited UV-visible absorption peaks at 370 nm, corresponds to a band gap of 3.24 eVand 3.08 eV respectively. Based on the above characterization techniques, the incorporation of silver affects the structural and optical behaviour of ZnO nanoparticles. The ZnO nanoparticles were observed that the particles are spherical morphologies. EDAX spectrum indicates no other elemental presence in the synthesized nanoparticle. The present work illustrate the Ag-ZnO nanoparticles as a photo-catalyst to decompose contaminants in the presence of UV light. The photo-catalytic activity of ZnO samples were investigated by UV- irradiation of methylene blue solution in a photocatalytic setup. The resulting mixtures were irradiated with UV light for a period of 45 mins. Based on results, the photocatalytic activity of Ag-ZnO nanoparticles were enhanced by the addition of Ag in pure ZnO nanoparticles. Ag doped ZnO nanoparticles showed higher photocatalytic activity efficiency than pure ZnO nanoparticles.