Photoelectrochemical response from CdSe-sensitized anodic oxidation TiO2 nanotubes

Uniform TiO2 nanotube arrays were fabricated on titanium substrates by self-organized anodic oxidation. CdSe quantum dots (QDs) were assembled onto TiO2 nanotube layers, which serve as sensitizers. The photocurrent measurement shows that annealing is essential to increase the anatase phase and hence increase the photocurrent. Attachment of CdSe QDs dramatically increased the photocurrent of TiO2 nanotubes in the visible region. The photo-response of CdSe sensitized TiO2 also shows strong dependence to the QDs size. The possible mechanism for energy transfer between the CdSe QDs and the TiO2 nanotubes has been discussed.