Fabrication, characterization and photoelectrochemical performance of chromium-sensitized titania nanotubes as efficient photoanodes for solar water splitting

Chromium-sensitized titanium dioxide nanotubes (CTNT) with high photocatalytic activity were prepared by a chemical bath deposition technique. The resulting films were characterized by SEM, EDX, and XRD. Results showed that the fabricated films have the ordered nanotubes with diameter of 90-140 nm, wall thickness of 20-50 nm, and tube lengths in the range of 24 mu m. Diffuse reflectance spectra showed an increase in the visible absorption relative to bare titanium dioxide nanotubes (TNT). The photoelectrochemical performance was examined under light irradiation in 1 M NaOH electrolyte. Photoelectrochemical characterization shows that chromium sensitizing efficiently enhances the photocatalytic water splitting performance of CTNT composite. The sample (C3TNT) exhibited better photocatalytic activity than the TNT and CTNT fabricated using other chromium concentrations. This inexpensive photoanodes prepared free of noble metals showed enhanced high photocurrent density with good stability and is a highly promising photoanode for solar hydrogen production.