Highly porous TiO2/Al2O3 composite nanostructures on glass by anodization and the sol–gel process: fabrication and photocatalytic characteristics

Abstract

Three-dimensional highly porous TiO₂(–4%SiO₂–1%TeO₂)/Al₂O₃ composite nanostructures directly fixed on glass substrates are fabricated by anodization of a superimposed Al/Ti layer sputter-deposited on glass and a sol–gel process. The porous composite nanostructures (Ø 30–120 nm), with a surface layer containing anatase TiO₂ with a preferential {004} reflection, possess large surface areas and exhibit an enhanced photocatalytic performance. In particular, the porous TiO₂–4%SiO₂–1%TeO₂/Al₂O₃ composite nanostructure with Ø ∼ 120 nm pores shows the highest photocatalytic activity (quantum yield) and is 6 times higher than the commercial Degussa P-25 TiO₂ powder under the experimental conditions.