Novel Ag decorated, BiOCl surface doped AgVO3 nanobelt ternary composite with Z-scheme homojunction-heterojunction interface for high prolific photo switching, quantum efficiency and hole mediated photocatalysis

Abstract

A ternary composite Ag@AgVO3/BiOCl possessing homojunction-heterojunction interface with varied BiOCl concentration was obtained through a facile hydrothermal route. Ag deposition in Ag@AgVO3 nano-belt was achieved through in-situ generation and deposition of Ag forming a homojunction. Whereas Ag@AgVO3/BiOCl heterojunction was constructed through the surface doping. This unique two-way interaction and the interface formation were revealed through the electron microscope and crystallographic analysis. The localized surface plasmon resonance of Ag and the efficient orbital mixing with BiOCl of 1:1 B/Ag@A compound has imparted a remarkable light harvesting and photo switching ability in the ternary composite material. Conductive nature of the Ag nanoparticle has promoted light absorption in the visible region and reduced the charge transfer resistance. Reduction of width in space charge region along with the increase in the amount of surface charge carrier has resulted in an outstanding increment in photocurrent. The solar photocatalysis evaluated against the aqueous phase removal of methyl orange and Bisphenol A showed 100 % and 51 % removal in 50 and 240 min, respectively. Studies were extended to understand the sensitization effect of dye. Theoretical modelling of band structure drawn from charge trapping experiments showed the prevalence of Z-scheme mechanism with holes mediated catalytic degradation. Improved charge harvest, separation and transmission has inserted a higher quantum efficiency in the material. BPA removal was enhanced to 82 % after the peroxide activation.