TiO2/Ti3C2 as an efficient photocatalyst for selective oxidation of benzyl alcohol to benzaldehyde

The TiO2/Ti3C2 composites performed excellent conversion efficiency and product selectivity. The enhanced photocatalytic activity could be ascribed to the existence of Ti3C2, which could improve charge separation, facilitate the O2 activation to generate more O2− active species and lower the VB level of TiO2 in the TiO2/Ti3C2 composites to avoid the over oxidation of BAD. [Display omitted] •The TiO2/Ti3C2 composite exhibits higher conversion efficiency and product selectivity than TiO2.•The presence of Ti3C2 could stabilize the oxygen vacancies and Ti3+ to promote the production of active intermediates.•The presence of Ti3C2 could lower the VB level to avoid the over oxidation. Photocatalytic selective oxidation of alcohols into corresponding aldehydes has received enormous attention. However, it remains a great challenge to explore photocatalysts with high conversion efficiency and selectivity. Herein, we developed a composite consisted of TiO2 and Ti3C2 through a simple calcination of Ti3C2 nanosheets. It was found that Ti3C2 could stabilize the oxygen vacancies and Ti3+ species in the TiO2/Ti3C2 composite, which could subsequent promote the production of active intermediates during the photocatalytic oxidation of benzyl alcohol (BA) to benzaldehyde (BAD). Additionally, the valence band of TiO2 in the composites was found to be up-shifted, which would avoid the further oxidation of BAD and enhance selectivity. As a result, the optimal composite exhibits the BA conversion efficiency of 97 % and BAD selectivity of 98 %, which is 2.8 and 1.2 folds higher than that of pristine TiO2. Our work may provide insights for designing efficient photocatalysts for selective oxidation of alcohols.