Synthesis of visible and near infrared light sensitive amorphous titania for photocatalytic hydrogen evolution

Abstract

A simple and environmentally safe method of anaerobic hydrolysis was designed to synthesize amorphous TiO_2−x containing Ti³⁺ from the dissolution of Ti⁰ by water in an anaerobic environment. The disordered arrangement of atoms in amorphous TiO_2−x enables it to expand its light absorbing boundary from the ultraviolet to near infrared light region by narrowing its mobility gap to 1.5 eV. As a result, an effective visible and near infrared light photocatalytic hydrogen evolution from water splitting can be achieved by the as-synthesized amorphous TiO_2−x with the aid of Ti³⁺ to inhibit charge recombination. An ideal quantum yield of approximately 4.57% was achieved at a wavelength of 488 nm. This strategy represents a new approach to alter the activity of TiO₂, and it is meaningful for achieving green production of artificial clean energy.