Metal/Metal Oxide\nModulation of RuNi Catalysts on\nTiO<sub>2</sub> Nanosheets Promoting Overall Water Splitting

Electrochemical\nwater splitting into hydrogen is deemed as an efficient\napproach for storing and utilizing renewable clean energy. Designing\nlow-cost and efficient catalysts is crucial for the large-scale production\nof hydrogen from water splitting. Herein, Ni-doped Ru catalysts supported\non the TiO<sub>2</sub> nanosheets were prepared by a two-step hydrothermal\nmethod and calcination in two different atmospheres (H<sub>2</sub>/Air) to obtain two types of RuNi–TiO<sub>2</sub>/Ti and Ru(Ni)O<sub>2</sub>–TiO<sub>2</sub>/Ti nanosheets. The TiO<sub>2</sub> nanosheets with large specific surface area are beneficial for dispersing\nnanoscale RuNi species. Furthermore, the RuNi catalyst firmly binds\nwith the TiO<sub>2</sub> nanosheets and enhances the electrochemical\nstability. Accordingly, the constructed Ru(Ni)O<sub>2</sub>–TiO<sub>2</sub>/Ti∥RuNi–TiO<sub>2</sub>/Ti exhibits superior\noxygen evolution reaction (OER) and hydrogen evolution reaction (HER)\nperformance. Such excellent performance could be ascribed to the rich\nspecific surface area of TiO<sub>2</sub> nanosheets, the synergistic\neffect between Ru and Ni, and their strong metal–support interaction\n(SMSI), which regulates the electronic structure of the active sites\nand increases the electrochemically active area, thus promoting their\ncatalytic performance during overall water splitting.