Single-atomic Pt sites anchored on defective TiO2 nanosheets as a superior photocatalyst for hydrogen evolution

Single-atomic site catalysts have drawn considerable attention because of their maximum atom-utilization efficiency and excellent catalytic activity. In this work, a highly active single-atomic Pt site photocatalyst was synthesized through employing defective TiO2 nanosheets as solid support for photocatalytic water splitting. It indicated that the surface oxygen vacancies on defective TiO2 nanosheets could effectively stabilize the single-atomic Pt sites through constructing a three-center Ti–Pt–Ti structure. The Ti–Pt–Ti structure can hold the stability of isolated single-atomic Pt sites and facilitate the separation and transfer of photoinduced charge carriers, thereby greatly improving the photocatalytic H2 evolution. Notably, our synthesized photocatalyst exhibited a remarkably enhanced H2 evolution performance, and the H2 production rate is up to 13460.7 μmol·h−1·g−1, which is up to around 29.0 and 4.7 times higher than those of TiO2 nanosheets and Pt nanoparticles-TiO2. In addition, a plausible enhanced reaction mechanism was also proposed combining with photo-electrochemical characterizations and density functional theory (DFT) calculation results. Ultimately, it is believed that this work highlights the benefits of a single-site catalyst and paves the way to rationally design the highly active and stable single-atomic site photocatalysts on metal oxide support.