Preparation of Mesoporous TiO₂/Co₃O₄ Nanosheets for Efficient Photocatalytic Oxygen and Hydrogen Evolution

TiO2-based two-dimensional nanosheet composite materials are promising photocatalysts for water splitting. The mesoporous structure possesses a high surface-to-volume ratio with more active sites. It is fantastic for photocatalysts to integrate the advantages of a porous structure into two-dimensional materials. The calcined ultrathin layered double hydroxides (LDHs) are porous metal oxide nanosheets, which are considered ideal templates to construct photocatalysts. In this work, we report the design and fabrication of amorphous aluminum oxide-supported anatase TiO2/spinel Co3O4 (TiO2/Co3O4) mesoporous nanosheets by calcinating ultrathin TiO2/CoAl-LDH precursors. The built-in electric field in the TiO2/Co3O4 interface facilitates the charge transfer, and Co3O4 acts as a cocatalyst to further enhance the oxygen evolution reaction activity. Consequently, the TiO2/Co3O4 photocatalyst exhibits excellent photocatalytic performances for the evolution of O2 and H2. This strategy for preparing mesoporous nanosheet photocatalysts is expected to extend to the other metal oxide semiconductor systems