Fe-TiO2-x/TiO2 S-scheme homojunction for efficient photocatalytic CO2 reduction.

[Display omitted] • A novel Fe-TiO 2-x /TiO 2 S-scheme homojunction was constructed. • The Fe-TiO 2-x /TiO 2 exhibits optimized CO/CH 4 generation rates of 122/22 μmol g-1h−1. • The role of OV and Fe in improving catalytic performance has been discussed. • The photocatalytic mechanism was detailedly analyzed. CO 2 -to-high value-added chemicals via a photocatalytic route is of interest but strangled by the low efficiency. Herein, a novel Fe-TiO 2-x /TiO 2 S-scheme homojunction was designed and constructed by using a facile surface modification approach whereby oxygen vacancy (OV) and Fe introducing on the TiO 2 nanorod surface. The as-synthesized Fe-TiO 2-x /TiO 2 S-scheme homojunction exhibits positive properties on promoting photocatalytic CO 2 reduction: i) the nanorod structure provides numerous active sites and a radical charge transfer path; ii) the doped Fe and OV not only synergistically enhance light utilization but also promote CO 2 adsorption; iii) the Fe-TiO 2-x /TiO 2 S-scheme homojunction benefits photoexcited charge separation and retains stronger redox capacity. Thanks to those good characters, the Fe-TiO 2-x /TiO 2 homojunction exhibits superior CO 2 reduction performances with optimized CO/CH 4 generation rates of 122/22 μmol g-1h−1 which exceed those of pure TiO 2 by more than 9.4/7.3 folds and most currently reported catalytic systems. This manuscript develops a facile and universal approach to synthesize well-defined homojunction and may inspire the construction of other more high-efficiency photocatalysts toward CO 2 reduction and beyond. [ABSTRACT FROM AUTHOR]