Preparation of reduced titanium dioxide assisted by hydrogen spillover

Abstract

Hydrogen spillover is a surface phenomenon that occurs on noble-metal-deposited reducible support. This process is initiated by the dissociation of hydrogen molecules, and then the hydrogen atom migrates from the metal particle to the surface of the support. A reduction assisted by the hydrogen spillover process can reduce metal cation and form an oxygen vacancy. In this work, reduced titanium dioxide with nanorod shape (TiO_2−x) was developed, via the reduction treatment assisted by hydrogen spillover under mild reduction conditions. In the ESR analysis, the signals attributed to Ti³⁺ and oxygen vacancy were observed after the reduction treatment, and their amount increased with an increase of the reduction temperature. The photocatalytic activity over the obtained titanium dioxide nanorod photocatalyst reduced at the lower temperature exhibited the highest activity under visible light irradiation. These results suggested that Ti³⁺ induced via the reduction assisted by hydrogen spillover improved photogenerated electron conductivity which led to the enhancement of the photocatalytic activity.