Enhanced photocatalytic activity of three-dimensional TiO2/reduced graphene oxide aerogel by efficient interfacial charge transfer

Abstract

TiO2 is one of the most widely used photocatalytic semiconductors. However, the rapid recombination of photogenerated electron-hole pairs severely weakens its photocatalytic activity. Herein, a three-dimensional TiO2/reduced graphene oxide (TiO2-rGO) aerogel with enhanced interfacial charge transfer was synthesized by a facile hydrothermal method, and its photocatalytic degradation of Methylene Blue (MB) and Reactive Red 24 (RR24) dyes was investigated. The photocatalytic results showed that TiO2–rGO aerogel possesses excellent photocatalytic activity, and its photocatalytic degradation rate towards dyes is more than 3.8 times that of pure TiO2 and more than 2.7 times that of TiO2-GO aerogel. Characterization results indicated that the significantly enhanced photocatalytic activity of TiO2-rGO aerogel could be attributed to the enhanced π–conjugated structure of rGO, which can effectively increase interfacial charge transfer and inhibit electron-hole pairs recombination. The mechanism suggested that OH and O2− are the active species in the photocatalytic degradation process. Our findings can provide an important reference for the preparation of high-performance TiO2-based photocatalysts.