Self-modification of TiO2 one-dimensional nano-materials by Ti3+ and oxygen vacancy using Ti2O3 as precursor

Abstract

One-dimensional (1D) titanium dioxide (TiO₂) nanowires and nanobelts have been fabricated via a hydrothermal synthesis and subsequent calcination process in different atmospheres. Ti₂O₃ was used as a raw material to directly provide Ti³⁺ in the resulting TiO₂ nanomaterials. The Ti³⁺ concentration in TiO₂ could be adjusted by annealing TiO₂ precursors in different atmospheres. The photocatalysis activity of samples calcinated in air or nitrogen with different Ti³⁺ concentrations was investigated. By means of analyzing photocatalytic degradation curves, 1D TiO₂ nanowires calcinated in nitrogen revealed enhanced photocatalysis activity compared with that one calcinated in air while the TiO₂ nanobelts exhibited an opposite result. The enhanced photocatalytic activity is ascribed to the enhanced light absorption from the narrowing band gap. The proper concentrations of Ti³⁺ and oxygen vacancies result in the efficient separation of photo-generated charge carriers in these nanomaterials.