In-situ Cr doped anodized TiO2 nanotubes with increased photocurrent response

Low-content chromium (Cr) doped titania nanotubes were grown by electrochemical anodization of Ti-Cr alloys in ethylene glycol electrolyte at varying time of anodisation to control the length of the tubes. Surface properties and photocurrent response of anodized layers after annealing at 450-750◦C were evaluated. Nanotubes with 0.02 at% Cr doping activated at 450◦C show a considerably increased photocurrent in comparison to pure anatase titania. This photocurrent increase of the Cr doped titania nanotubes is ascribed to higher anatase crystallinity and lower photoelectrochemical recombination losses.