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

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 (empty set 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 empty set similar to 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.