Facile fabrication of 3D TiO2 - graphene aerogel composite with enhanced adsorption and solar light-driven photocatalytic activity

Three-dimensional (3D) titanium dioxide – graphene aerogels (TA-TiO2-GA) with network architectures and in-situ growth of TiO2 NPs onto its surface were facilely self-assembled via one-step hydrothermal treatment by employing tannic acid (TA). TA as the reducing agent and linker promoted a strong coupling between the graphene and TiO2. The TA-TiO2-GA exhibited good photocatalytic performance and reusability in the degradation of typical organic contaminants: upon 3 h simulated solar irradiation, the removal rate of tetracycline, methylene blue and rhodamine B reached 43.2%, 77.8%, and 91.9%, respectively; nearly no deactivation of the TA-TiO2-GA was observed after reuse of over10 cycles. Mechanistic studies indicated that the synergy of adsorption and photocatalysis played an important role, and superoxide radical anions and hydroxyl radicals are the major reactive oxidative species. To conclude, this study provides a novel alternative to fabricate 3D TA-TiO2-GA which has great potential in solar light-driven environmental applications.