A comparative study on metal species implanted amine–brookite–TiO 2 nanorods for enhanced photocatalytic CO 2 reduction

Semiconductor-based photocatalytic carbon dioxide (CO 2 ) reduction is of great scientific importance in the field of alleviating global warming and energy crisis. Surface amine modification and cocatalyst loading on the catalyst surface could improve CO 2 adsorption capacity and photogenerated charge separation. Herein, amine-modified brookite–TiO 2 (NH 2 –B–TiO 2 ) coupled metal species (Cu, Ag, Ni(OH) 2 ) cocatalysts have been successfully synthesized by chemical reduction method. The photocatalytic CO 2 reduction results show that the CH 4 production rates of NH 2 –B–TiO 2 /Cu, NH 2 –B–TiO 2 /Ag, and NH 2 –B–TiO 2 /Ni(OH) 2 are 3.2, 12.5, and 1.7 times that of NH 2 –B–TiO 2 (0.74 μmmol g −1 h −1 ), respectively. Results show the introduction of metal species on the surface of the catalyst enhances the absorption range of sunlight and the photogenerated carrier separation efficiency, resulting in enhancing the performance of photocatalytic CO 2 reduction. This work provides a strategy for designing metal species-loaded amine-modified brookite–TiO 2 by surface/interface regulation to improve photocatalytic efficiency. Graphical abstract