Excellent photocatalytic activity of ternary Ag@WO3@rGO nanocomposites under solar simulation irradiation

Abstract

The ternary nanocomposite of Ag@WO3@rGO was synthesized via a two-step hydrothermal method in which the binary composite of the Ag-doped WO3 (Ag@WO3) prepared by the 1st hydrothermal step was combined with the reduced graphene oxide (rGO) via the ultrasonic-assisted 2nd hydrothermal step. The composition with Ag and rGO helped to reduce the optical bandgap energy of WO3, and thereby to enhance the photocatalytic activity of the WO3–based nanocomposites. When compared with the pristine WO3 sample under the solar simulation irradiation, the binary (Ag@WO3) nanocomposite showed the increased photocatalytic activity towards the degradation of Rhodamine B (RhB) from 23% (pristine WO3) to 80% (Ag@WO3). Notably, the ternary nanocomposite exhibited an excellent photocatalytic efficiency of RhB degradation (99.5%). The significantly enhanced photocatalytic activity was assigned to the combined synergy effects of the electron-reservoir of Ag and the highly absorptive r-GO with the visible-band gap WO3 semiconductors, which suggests a promising procedure to construct ternary nanocomposite-based high-performance photocatalysts under the solar light. © 2020 The Authors