Effective charge separation and enhanced photocatalytic activity by the heterointerface in MoS2/reduced graphene oxide composites

Abstract

MoS₂/reduced graphene oxide (rGO) composites were fabricated via a facile one-step hydrothermal reaction. In the composites, MoS₂ clusters composed of several nanosheets are intertwined tightly with rGO sheets. As the amount of rGO in the composites is increased, the crystallinity of MoS₂ changes little, but the diameter of MoS₂ clusters decreases considerably and they become more dispersive, resulting in a large specific surface area. As compared to the bare MoS₂, the as-prepared MoS₂/rGO composites exhibit remarkably enhanced light adsorption and photocatalytic activity for the degradation of Rhodamine B (RhB) under visible light irradiation. Photoluminescence (PL) spectra measurements suggest that the enhanced photocatalytic properties can be ascribed to the effective charge separation across the heterointerface in MoS₂/rGO composites. It is also demonstrated that the optical and photoelectric properties of two-dimensional (2D) materials could be substantially enhanced by the heterojunction with an appropriate band edge alignment, since they possess the largest specific surface area.