The Photoelectrochemical Response of Various Surface Morphologies of Titanium Anodic Oxide Films

Anodic oxide films of Titanium (Ti) with different surface morphologies were investigated by controlling the content of NH4F in EG electrolyte. When Ti was anodised in the low content of NH4F (1 wt%), a thin TiO2 compact oxide layer was formed. However, TiO2 nanoporous structure appeared on the surface of Ti when 3 wt% of NH4F was added. When NH4F was further increased to 5 wt%, a self-ordered nanotubular oxide structure was observed. TiO2 nanotubular structure exhibited higher photocurrent density (~0.45 mA cm–2) as compared to the nanoporous and compact oxide layer.