Fluorine‐Induced Surface Metallization for Ammonia Synthesis under Photoexcitation up to 1550 nm

Abstract

The first observation of surface metallization of TiO_2-x induced by fluoride ions is presented. The emerging metallic states are contributed by the 3d orbital of surface Ti and the 2p orbital of surface bridging F, which are intrinsically originated from the strong electron repulsion between F^- and adjacent Ti³⁺ . The metalized TiO_2-x with reduced work function and downward band bending possesses high electron-donating power to supported Ru species via atomic-scale ohmic contacts, exhibiting unprecedented photocatalytic performances for ammonia synthesis across the entire solar spectrum region (200-1550 nm) at room temperature. Mechanism and kinetic analysis revealed that the loaded Ru could behave as efficient electron sinks to accumulate photogenerated electrons and that the metallic surface markedly enhanced the dissociation of H₂ and N₂ by the hot electrons generated by the visible or even infrared light irradiation.