Supercritical CO2 produces the visible-light-responsive TiO2/COF heterojunction with enhanced electron-hole separation for high-performance hydrogen evolution

To construct the heterojunctions of TiO 2 with other compounds is of great importance for overcoming its inherent shortages and improving the visible-light photocatalytic performance. Here we propose the construction of TiO 2 /covalent organic framework (COF) heterojunction with tight connection by a supercritical CO 2 (SC CO 2 ) method, which helps bridging the transformation paths for photo-induced charge between TiO 2 and COF. The produced TiO 2 /COF heterojunction performs a H 2 evolution of 3,962 µmol·g −1 ·h −1 under visible-light irradiation, which is ∼ 25 times higher than that of pure TiO 2 and 4.5 folds higher than that of TiO 2 /COF synthesized by the conventional solvothermal method. This study opens up new possibilities for constructing heterojunctions for solar energy utilization.