Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods

Abstract

The immobilization of miniscule quantities of RuO 2 (∼0.1%) onto one-dimensional (1D) TiO 2 nanorods (NRs) allows H 2 evolution from water under visible light irradiation. Rod-like rutile TiO 2 structures, exposing preferentially (110) surfaces, are shown to be critical for the deposition of RuO 2 to enable photocatalytic activity in the visible region. The superior performance is rationalized on the basis of fundamental experimental studies and theoretical calculations, demonstrating that RuO 2 (110) grown as 1D nanowires on rutile TiO 2 (110), which occurs only at extremely low loads of RuO 2, leads to the formation of a heterointerface that efficiently adsorbs visible light. The surface defects, band gap narrowing, visible photoresponse, and favorable upward band bending at the heterointerface drastically facilitate the transfer and separation of photogenerated charge carriers.