A novel UV and visible light driven photocatalyst AgIO4/ZnO nanoparticles with highly enhanced photocatalytic performance for removal of rhodamine B and indigo carmine dyes

A novel visible light driven AgIO4/ZnO photocatalyst containing various proportions of AgIO4 contents [0-20] wt% were synthesized for successful photodegradation of rhodamine B and indigo carmine dyes under UV and natural sunlight radiations. The as-synthesized nanoparticles were characterized by XRD, FTIR, N-2-adsorption desorption isotherm, DRS, PL and HRTEM. A homogeneous distribution of mesoporous AgIO4 nanoparticles with surface area (32 m(2)/g), ink-bottle pore structure and narrow band gap energy (2.1 eV) was formed on cubic ZnO surface. The formation of AgIO4/ZnO heterostructure photocatalyst is significantly reduced the band gap energy to 2.23 eV revealing a generation of new matching band potential that responsible for shifting the photocatalytic response to visible region. The as-achieved AgIO4/ZnO nanoparticles exhibits an excellent photoreactivity and stability toward degradation of RhB and IC dyes with optimal concentration 15 wt % AgIO4 that is responsible for removal 98 % of IC and 81 % of RhB dyes. The excellent photocatalytic reactivity was attributed to the electron transfer during the photocatalytic process from conduction band of ZnO (E-CB = -0.34 eV) to conduction band of AgIO4 (E-CB= + 0.96). Electron conduction band and superoxide radicals are the main reactive species for dye degradation over AgIO4 and ZnAg15. However, positive hole and hydroxyl radicals exhibit the predominant role on ZnO surface. Moreover, benefited from the excellent photoreactivity of ZnAg15, the photocatalyst can be regenerated after five consecutive cycles revealing the high photostability of the nanoparticles. A possible mechanism for the photocatalytic process is proposed.