Plasmon Mediated Photocatalysis by Solar Active Ag/ZnO Nanostructures: Degradation of Organic Pollutants in Aqueous Conditions

Abstract

NanotechnologyAbstractIntroductionPresent article focuses on the in-situ generated Ag/ZnO nano catalyst for effluent treatment. It is observed that synthesis of the catalyst using starch as environment friendly surfactant resulted in plate like elongated Zinc Oxide nanoparticles. As-synthesized catalyst is characterized by X-Ray Diffraction measurement confirming hexagonal ZnO and fcc silver. XRD, further revealed d-spacings of 0.26 and 0.234 nm for ZnO and Ag/ZnO indicating the correctness of their crystal structures. FESEM, EDX and TEM, showed spherical but flat plate type morphology due to presence of starch. XPS confirmed oxygen rich composition and UV-Vis spectrophotometry revealed decrease in band gap energies with increasing silver loading. The photocatalytic performance of the plasmonic catalysts was studied under direct sunlight. Degradation of aqueous solutions of Methylene Blue (MB) Rhodamine B (RhB), Methyl Orange (MO), Bromophenol Blue (BPB) and p-nitrophenol (PNP) was monitored by absorption spectroscopy to reveal complete degradation of organic dyes. It was observed that the catalyst retained its properties even after third recycle. Such simple catalyst may offer ready solution for effluent treatment under direct sunlight.