Fe-TiO/TiO S-scheme homojunction for efficient photocatalytic CO reduction.

CO-to-high value-added chemicals via a photocatalytic route is of interest but strangled by the low efficiency. Herein, a novel Fe-TiO/TiO S-scheme homojunction was designed and constructed by using a facile surface modification approach whereby oxygen vacancy (OV) and Fe introducing on the TiO nanorod surface. The as-synthesized Fe-TiO/TiO S-scheme homojunction exhibits positive properties on promoting photocatalytic CO 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 adsorption; iii) the Fe-TiO/TiO S-scheme homojunction benefits photoexcited charge separation and retains stronger redox capacity. Thanks to those good characters, the Fe-TiO/TiO homojunction exhibits superior CO reduction performances with optimized CO/CH generation rates of 122/22 μmol gh which exceed those of pure TiO 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 reduction and beyond.