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 TiO_2- nanosheets (NSs), mainly including two facets of (001) and (101), with loading of Pt nanoparticles (NPs) at their edges (Pt/TiO_2--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/TiO_2--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 TiO_2- NSs upon 365 nm light irradiation. The high H₂ generation rate (607 mmol g_cata^-1 h^-1) of Pt/TiO_2--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.