Surface Engineering of TiO2 Nanosheets to Boost Photocatalytic Methanol Dehydrogenation for Hydrogen Evolution

Low-cost high-efficiency H2 evolution is indispensable for its large-scale applications in the future. In the research, we expect to build high active photocatalysts for sunlight-driven H2 production by surface engineering to adjust the work function of photocatalyst surfaces, adsorption/desorption ability of substrates and products, and reaction activation energy barrier. Single-atom Pt-doped TiO2–x nanosheets (NSs), mainly including two facets of (001) and (101), with loading of Pt nanoparticles (NPs) at their edges (Pt/TiO2–x -SAP) are successfully prepared by an oxygen vacancy-engaged synthetic strategy. According to the theoretical simulation, the implanted single-atom Pt can change the surface work function of TiO2, which benefits electron transfer, and electrons tend to gather at Pt NPs adsorbed at (101) facet-related edges of TiO2 NSs for H2 evolution. Pt/TiO2–x -SAP exhibits ultrahigh photocatalytic performance of hydrogen evolution from dry methanol with a quantum yield of 90.8% that is ∼1385 times higher than pure TiO2–x NSs upon 365 nm light irradiation. The high H2 generation rate (607 mmol gcata –1 h–1) of Pt/TiO2–x -SAP is the basis for its potential applications in the transportation field with irradiation of UV–visible light (100 mW cm–2). Finally, lower adsorption energy for HCHO on Ti sites originated from TiO2 (001) doping single-atom Pt is responsible for high selective dehydrogenation of methanol to HCHO, and H tends to favorably gather at Pt NPs on the TiO2 (101) surface to produce H2.