Self-organized TiO2 nanotube arrays by anodization of Ti substrate:: Effect of anodization time, voltage and medium composition on oxide morphology and photoelectrochemical response

This study probes the relationship between the morphology of anodic titania (TiO2) layers grown on Ti foil substrates and their subsequent photoelectrochemical response in 0.5 M Na2SO4 supporting electrolyte. The effects of anodization variables (voltage and time) and anodization medium composition [water, glycerol, poly(ethylene glycol), ethylene glycol] along with fluoride ion concentration on the oxide layer of morphology and photoresponse are described. The degree of order of the self organized TiO2 nanotube arrays and the extent to which these arrays organize themselves over the entire substrate surface are key variables dictating the corresponding quality of the resultant photoresponse.