Ions-exchange anchoring Cu7S4 cocatalyst on K2Ti8O17 nanowires assembly for enhanced CO2 photoreduction through efficient charge separation

Photocatalytic CO 2 reduction into solar fuels has received increasing attention because it is a promising approach to tackle the environment and energy issues we are currently facing. Herein, the composite of K 2 Ti 8 O 17 nanowires assembly coupled with Cu 7 S 4 cocatalyst has been successfully prepared by an ion exchange method, in which the CuCl is employed as the copper source to convert CdS to Cu 7 S 4 . The photocatalytic performance of the integrated K 2 Ti 8 O 17 -Cu 7 S 4 composite is evaluated by CO 2 photoreduction, and it exhibits superior photoreduction capability than pristine K 2 Ti 8 O 17 nanowires assembly. In particular, the K 2 Ti 8 O 17 -Cu 7 S 4 -0.2 sample displays the highest CH 4 (6.02 μmol g −1 h −1 ) and CO (0.89 μmol g −1 h −1 ) yield within 4 h light irradiation, which is 3.83 and 12.71 times higher than that of K 2 Ti 8 O 17 sample, respectively. Based on the photo/electrochemical test results, the anchoring of Cu 7 S 4 cocatalyst can promote the photogenerated electron-hole pairs separation and charge transfer of the K 2 Ti 8 O 17 , which contributes to more photogenerated electrons participating in the process of photocatalytic CO 2 reduction to CH 4 . This work offers a promising approach to design efficient noble-cocatalyst-free photocatalyst for CO 2 photoreduction.