Synthesis of Ag-ZnO nanoparticles for enhanced photocatalytic degradation of acid red 88 in aqueous environment

Photocatalytic activities were found to be enhanced when noble metals were deposited on the semiconductors because the metal nanoparticles store electrons within them and in turn are recognized to act as a sink for photoinduced charge carriers, promoting interfacial charge transfer processes. This motivates us to modify the bare ZnO powder by doping with nano sized silver to yield metal-semiconductor nanocomposites by simple material syntheses route to suppress detrimental recombination of the photogenerated charge carriers. The materials were characterized by different analytical techniques and it is potentially utilized for the photocatalytic degradation of an azo dye (Acid Red 88; AR88) in the visible region (λ>400 nm). A possible mechanism for the photocatalytic degradation of AR88 by Ag-ZnO in the absence and presence of other oxidizing agents (peroxomonosulfate (PMS), peroxodisulfate (PDS) & hydrogen peroxide (H₂O₂)) has been proposed. The extent of mineralization of the target pollutant was also evaluated using Total Organic Carbon (TOC) analysis.