SYNTHESIS AND CHARACTERIZATION OF Ag-ZnO/Ag3PO4 NANOCOMPOSITES FOR PHOTOREDUCTION STUDY OF HEXAVALENT CHROMIUM IN AQUEOUS SOLUTION

Abstract

The binary systems of Ag3PO4/ZnO and doped Ag-ZnO/Ag3PO4 nanocomposites were synthesized by a co-precipitation method. The obtained nanocomposites were calcined at 400oC, 500oC, 600o c and 700oC for 3h. The structures, morphology, compositions and band gap energies of the composites were studied using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Despersive X-ray (EDX) and UV- visible spectroscopy. In this work, the photoreduction of hexavalent chromium in aqueous solution using Ag-ZnO/Ag3PO4 nanocomposites as photocatalyst has been investigated using UV-VIS measurement. The photocatlytic performance of the doped binary system calcined at high temperature (700 oC) was found to be the one resulting in relatively higer photoreduction efficiency. However, generally the photoreduction efficiency of these materials were found to be lower (< 50 %) perhaps due to lack of optimization of the whole photocatalytic parameters.