Tuning the surface charge of graphene for self-assembly synthesis of a SnNb2O6 nanosheet–graphene (2D–2D) nanocomposite with enhanced visible light photoactivity

Abstract

A two-dimensional (2D) SnNb₂O₆ nanosheet–graphene (SnNb₂O₆–GR) nanocomposite featuring a typical 2D–2D structure has been synthesized via a simple surface charge modified self-assembly approach. The method is afforded by electrostatic attractive interaction between negatively charged SnNb₂O₆ nanosheets and modified graphene nanosheets with a positively charged surface in an aqueous solution. The SnNb₂O₆–GR nanocomposite exhibits a distinctly enhanced visible light photocatalytic performance toward degradation of organic dye in water as compared to blank SnNb₂O₆ nanosheets. The enhanced photoactivity is attributed to the integrated factors of the intimate interfacial contact and unique 2D–2D morphology associated with SnNbO₆ and GR, which are beneficial for harnessing the electron conductivity of GR, facilitating the transfer and separation of photogenerated charge carriers over SnNbO₆–GR upon visible light irradiation, and thereby contributing to the photoactivity enhancement. It is hoped that this work could enrich the facile, efficient fabrication of various 2D–2D semiconductor nanosheet–graphene composite photocatalysts toward target photocatalytic applications.