Controlled anodic growth of TiO2 nanobelts and assessment of photoelectrochemical and photocatalytic properties

• We prepared successfully immobilized TiO2 nanobelts by electrochemical anodization.
• The morphology of TiO2 nanobelts is controlled by the composition of electrolyte, applied voltage and anodization time.
• The formation of TiO2 nanobelts is a combined result of field-assisted etching and chemical dissolution.
• The TiO2 nanobelts exhibit higher photoelectrochemical and photocatalytic activities than nanotubes.

We report on the formation of TiO2 nanobelts (NBs) by electrochemical anodization of titanium in an electrolyte comprised of water, NH4F and ethylene glycol. The morphology of TiO2 NBs is considerably controlled by the composition of electrolyte, applied voltage, anodization time and calcination temperature. We find that the TiO2 NBs originate from nanotubes (NTs), and it is the combined result of field-assisted etching and chemical dissolution at the mouth of tubes. The TiO2 NBs bend and deflect into bundles due to the action of capillary forces between adjacent NBs during the postgrowth cleaning and evaporative drying process. Furthermore, we evaluate the photoelectrochemical (PEC) and photocatalytic (PC) performance of the TiO2 NBs, with results suggesting that the TiO2 NBs exhibit higher PEC and PC activities than NTs owing to its specific morphology. This TiO2 nanostructure is expected to be applied in pollutants elimination, photocatalytic decomposition of water and other novel applications.