Netted C-Doped TiO₂ Mesoporous Nanostructure Decorated by Cu Nanoparticles for Photocatalytic CO₂ Reduction

Acquiring an anatase TiO2 catalyst with tiny size and high crystallinity for excellent photocatalytic performance still remains a huge challenge. Herein, a mesoporous C-doped TiO2 netted nanostructure is successfully synthesized by a vacuum dipping and calcination method, where the thin film of multiwalled carbon nanotubes is skillfully utilized as the confinement template to suppress the grain growth and phase transfer. In addition, small Cu nanoparticles are deposited on the surfaces of the TiO2 by an electronic beam evaporation way. The obtained C–TiO2–Cu photocatalyst exhibits high CH4 and CO production rates of 8.8 and 60.3 μmol/g/h, respectively, which are excellent among the TiO2-based photocatalysts. This high performance originates from the following synergistic effects. This good crystalline and small size can facilitate the charge separation, while this unique netted mesoporous structure will provide sufficient sites for the reaction. Moreover, the C doping can enhance light absorption and the plasmonic Cu can inject hot electrons into TiO2, which will increase the amounts of electrons and promote their transfer.