Oxygen Vacancy-Modified TiO<sub>2</sub>/Ti<sub>3</sub>C<sub>2</sub>/CdS Nanocomposites for Photocatalytic Selective Oxidation of Amines
Yanfang Ge, Yuli Hu, Xiaojun Ma, Yongjuan Chen, Jiao He, Liang Jiang, Zhiying Yan, Jiaqiang Wang
Abstract
A TiO 2 /Ti 3 C 2 /CdS (TTCS) photocatalytic material with oxygen vacancies (OVs) was prepared by using a one-step solvothermal method, and it was applied for photooxidative coupling reactions involving benzylamine. Under the influence of dimethyl sulfoxide and high temperatures, most of the Ti 3 C 2 -MXene was oxidized into TiO 2 nanosheets and embedded on its surface. The decomposition simultaneously generated H 2 S, which could react with Cd 2+ to form CdS. In addition, it could reduce the thermodynamically unstable transition metal atoms on the surface of MXene, resulting in OVs in TiO 2 . The surface OVs not only activated the O 2 molecules adsorbed on the metal oxide photocatalyst surfaces to produce active oxygen but also formed shallow donor states that promoted photogenerated charge carrier separation. This TTCS composite achieved a high conversion of benzylamine with a relatively high selectivity of N-benzylbenzaldimine. This work not only provides ideas for synthesizing composite photocatalytic materials but also offers strategies for defect engineering regulation.