Short-Distance Hydrogen Spillover on an Isolated Amorphous RuTe x Cocatalyst for Superior Photocatalytic H 2 Evolution

Hydrogen spillover has been extensively demonstrated as an effective strategy to promote hydrogen evolution; however, in conventional binary-component catalysts, this process is often hindered by long spillover pathways and high interfacial resistance. Herein, we report an efficient short-distance hydrogen-spillover pathway achieved on an isolated amorphous RuTex cocatalyst, which obviously enhances the photocatalytic H2-evolution activity of TiO2. Upon loading RuTex nanoparticles onto the TiO2 surface (RuTex/TiO2), distance-dependent electron transfer from the RuTex cocatalyst to TiO2 induces a gradual change in the electronic structure of the Ru and Te active sites, resulting in a gradual increase in electron density from the bottom to the top of the RuTex nanoparticles. This gradient establishes two distinct functional regions within each nanoparticle: a strong H-adsorption region near the RuTex/TiO2 heterointerface (RuTex/TiO2(bottom)) and a strong H-desorption region away from the interface (RuTex/TiO2(top)), thereby enabling an efficient hydrogen spillover process within the isolated cocatalyst. As a result, the RuTex/TiO2 composite achieves a photocatalytic H2-production rate of 3.47 mmol·g-1·h-1 under alkaline conditions, which is 81.6 times higher than that of pure TiO2. This study opens an avenue for the design of catalysts with enhanced hydrogen spillover, paving the way for advanced H2 generation.