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

The TiO 2 /Ti 3 C 2 composites performed excellent conversion efficiency and product selectivity. The enhanced photocatalytic activity could be ascribed to the existence of Ti 3 C 2 , which could improve charge separation, facilitate the O 2 activation to generate more O2− active species and lower the VB level of TiO 2 in the TiO 2 /Ti 3 C 2 composites to avoid the over oxidation of BAD. • The TiO 2 /Ti 3 C 2 composite exhibits higher conversion efficiency and product selectivity than TiO 2. • The presence of Ti 3 C 2 could stabilize the oxygen vacancies and Ti3+ to promote the production of active intermediates. • The presence of Ti 3 C 2 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 TiO 2 and Ti 3 C 2 through a simple calcination of Ti 3 C 2 nanosheets. It was found that Ti 3 C 2 could stabilize the oxygen vacancies and Ti3+ species in the TiO 2 /Ti 3 C 2 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 TiO 2 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 TiO 2. Our work may provide insights for designing efficient photocatalysts for selective oxidation of alcohols. [ABSTRACT FROM AUTHOR]