Photoelectrochemical responses of anodized titanium oxide films

Thin titanium films of 200 nm thickness were prepared by physical vapor deposition over conducting glass plates and anodized to form titanium oxide nanostructured film that demonstrates photoactivity under ultraviolet visible (UV-vis) illumination. Absorbance and photoelectrochemical measurements indicate that the anodized and nitrogen annealed films absorb UV-vis (lambda = 300 to 800 nm) illumination to produce a current of 2.5 mA at 0 V and 3 mA at +0.4 V versus Ag/AgCl. A photocurrent of 110 mu A and an open-circuit photovoltage (V-OC) of 300 mV was noted without application of external bias. Long-term stability tests showed that the photocurrent was stable for 2 h under continuous illumination. The titanium oxide prepared from a small fraction of titanium deposited over conducting glass demonstrates almost similar activity compared with titanium oxides prepared on foils. The material offers promising potential in other applications such as environmental remediation and photocatalytic water splitting.