Defective TiO2 with increased photocatalytic activity synthesized by the TiO2/Ti interfacial reaction method

Defective TiO2 with a narrow band gap is conducive to maximizing the utilization of solar energy. Herein, atomic-scale insight into the TiO2/Ti interfacial reaction was obtained by molecular dynamics (MD) simulation. It is found that a large amount of oxygen in TiO2 diffuses into metallic Ti while limited Ti atoms in metallic Ti diffuse into TiO2 after the interfacial reaction, leading to a decrease in the concentration of oxygen in TiO2 as well as the formation of defective TiO2. With the enlightenment of the simulation results, defective TiO2 was efficiently synthesized by the TiO2/Ti interfacial reaction method, and its band gap was modulated from 3.26 to 2.54 eV. Additionally, chronoamperometry tests demonstrate that the synthesized defective TiO2 has an outstanding photocatalytic activity for hydrogen evolution. Therefore, the TiO2/Ti interfacial reaction method is an effective approach to reduce the band gap of TiO2 and enhance its photocatalytic activity.