A p-n Junction by Coupling Amine-Enriched Brookite-TiO 2 Nanorods with Cu x S Nanoparticles for Improved Photocatalytic CO 2 Reduction.

Photocatalytic CO 2 reduction is a promising technology for reaching the aim of "carbon peaking and carbon neutrality", and it is crucial to design efficient photocatalysts with a rational surface and interface tailoring. Considering that amine modification on the surface of the photocatalyst could offer a favorable impact on the adsorption and activation of CO 2 , in this work, amine-modified brookite TiO 2 nanorods (NH 2 -B-TiO 2 ) coupled with Cu x S (NH 2 -B-TiO 2 -Cu x S) were effectively fabricated via a facile refluxing method. The formation of a p-n junction at the interface between the NH 2 -B-TiO 2 and the Cu x S could facilitate the separation and transfer of photogenerated carriers. Consequently, under light irradiation for 4 h, when the Cu x S content is 16%, the maximum performance for conversion of CO 2 to CH 4 reaches at a rate of 3.34 μmol g -1 h -1 in the NH 2 -B-TiO 2 -Cu x S composite, which is approximately 4 times greater than that of pure NH 2 -B-TiO 2 . It is hoped that this work could deliver an approach to construct an amine-enriched p-n junction for efficient CO 2 photoreduction.