One-step synthesis of nonstoichiometric TiO₂ with designed (101) facets for enhanced photocatalytic H₂ evolution

Photocatalyst is widely applied in environmental remediation and energy conversion. Appropriately engineered band structures of semiconductor photocatalysts are beneficial for enhancing surface reactions under light irradiation. Exposing the highly reductive facets of TiO₂ crystals has been recognized as an efficient approach to promote photocatalytic reduction reaction. However, there is no report about the application of one-step solvothermal reaction for the synthesis of the TiO₂ crystals with (101) facets and in-situ doping. In this work, non-stoichiometric anatase TiO₂ microspheres with designed (101) facets were successfully synthesized by using one-step solvothermal reaction. The prepared non-stoichiometric anatase TiO₂ microspheres with designed (101) facets exhibited a great photocatalytic activity for H₂ evolution with a reaction rate of 3.4 times faster than that of anatase TiO₂ that was neither etched nor doped. The (101) facets of anatase TiO₂ were found to be able to generate and transmit more reductive electrons to promote the H₂ evolution in the photocatalytic reduction reaction. With the femtosecond time-resolved diffused reflectance measurement, the roles of self-doping Ti³⁺ as the photogenerated electrons trapping and (101) facets were further elucidated. Our findings might provide a new opportunity to develop an efficient, cost-effective and promising TiO₂-based catalyst for enhanced photocatalytic H₂ production.