Electrochemical synthesis of titania nanostructural arrays and their surface modification for enhanced photoelectrochemical hydrogen production

We synthesized nanostructured TiO2 photoanodes by electrochemical anodization with different geometries and investigated the effects of the electrode surface structure on the generation of hydrogen. The surface of the nanotubular photoanodes was then treated with helium plasma to remove contaminants and reduce the recombination sites. This was followed by nitrogen plasma treatment for surface doping with N2. Surface treatment created oxygen vacancies and induced substitutional doping of N2 at the titania surface. The results showed that the combination of novel surface structures coupled with plasma-assisted surface modification improves the photocurrent density of TiO2 photoanodes.