Constructing Ru/TiO2 Heteronanostructures Toward Enhanced Photocatalytic Water Splitting via a RuO2/TiO2 Heterojunction and Ru/TiO2 Schottky Junction

Photocatalysts based on metallic Ru and RuO 2 dual co‐catalysts modified TiO 2 nanobelts (NBs) are constructed through a wet‐impregnation reduction method with post thermal oxidation. The samples are characterized carefully and their photocatalytic activities for the half reactions of water splitting as well as full water splitting are evaluated systematically under solar light irradiation. The detailed characterizations and analyses clearly reveal the formation of a Schottky junction at the Ru‐TiO 2 interface and of RuO 2 /TiO 2 heterojunctions. The results of the photocatalytic tests show that both Ru and RuO 2 can improve the photocatalytic activity for H 2 /O 2 evolution and water splitting. Moreover, the photocatalytic activity of the TiO 2 NBs can be further enhanced by co‐modification with dual Ru and RuO 2 co‐catalysts. The RuO 2 /TiO 2 heterojunction improves the transfer of the photogenerated holes from the TiO 2 to the RuO 2 , where water can be oxidized by the holes to evolve O 2 , and the Ru/TiO 2 Schottky junction promotes the transfer of photogenerated electrons from the TiO 2 NBs to the metallic Ru for proton reduction into H 2 . These two processes are involved in the overall water splitting. This work provides an important reference for designing highly efficient photocatalysts for water splitting through loading of dual co‐catalysts containing the same element but with different valence structures.