Enhanced photocatalytic H 2 -production activity of anatase TiO 2 nanosheet by selectively depositing dual-cocatalysts on {101} and {001} facets

The photocatalytic hydrogen production using solar energy through water splitting has received great attention due to the increasingly serious energy crisis. Herein, we report the controlled preparation of anatase TiO2 nanosheet photocatalyst by selectively depositing Co3O4 nanoparticles (NPs) as water oxidation cocatalyst (WOC) and Pt NPs as water reduction cocatalyst (WRC) on {001} and {101} facets, respectively, using a two-step photodeposition method. The prepared TiO2-Co3O4-Pt composite photocatalyst exhibits a greatly enhanced photocatalytic H2-production activity at the optimal weight percentage of Co3O4 and Pt (both 1.0 wt%), exceeding that of TiO2 nanosheet deposited with single Co3O4 or Pt cocatalyst by 9.4 and 1.8 times, respectively. The enhanced H2-production activity is due to the synergetic effect of surface heterojunction between {001} and {101} facets and selective deposition of Co3O4 and Pt dual-cocatalysts at {001} and{101} facets, respectively. The former is beneficial for the transfer and separation of charge carriers, the latter can reduce the recombination rate of photogenerated electrons and holes and also catalyze the redox reactions. This work will provide a new route for the rational design and fabrication of highly efficient photocatalysts with dual-cocatalysts through selective surface deposition.