Synergetic effect of surface plasmon resonance and schottky junction in Ag-AgX-ZnO-rGO (X= Cl & Br) nanocomposite for enhanced visible-light driven photocatalysis

Abstract

Plasmonic photocatalysis has encouraged quick improvement in improving the photocatalytic activity under visible light illumination, augmenting the potential for utilizing light for ecological and energy application. Plasmonic photocatalysis utilizes noble metal nanoparticles embedded with semiconductor nanocatalyst and utilizes Schottky junction and surface plasmonic resonance (SPR). In this particular work, a novel photocatalyst Ag-AgX-ZnO-rGO (X = Cl & Br) was synthesized making use of a hydrothermal-photoreduction method by means of zinc nitrate, cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC), AgNO3, and also graphene oxide (GO), during the course of which the crystallization of ZnO, Ag nanoparticles generation, as well as reduction of GO to rGO were attained at the same time. Main essential benefits in plasmonic photocatalyst (Ag-AgX-ZnO-rGO) over a two-component (ZnO-rGO) system and detailed processes for improved photocatalytic activity in terms of band-edge positions have been proposed. The degradation mechanism of methylene orange (MO) was discussed based on the intermediate products detected by mass spectrometry analysis. Physical mechanisms of plasmonic enhancement for photocatalytic degradation of MO in terms of the band-bending and surface plasmon resonance have been discussed. In addition, comparisons are made between photo-oxidation and photo-reduction effectiveness in Ag-AgBr-ZnO-rGO and Ag-AgCl-ZnO-rGO plasmonic photocatalyst on the foundation of charge polarization.