Enhancement in Photoresponse of Hematite Photoanodes Nanostructures by Changing Morphology for Solar Water Splitting

Hematite (α-Fe2O3) is a promising semiconductor as photoanode in solar hydrogen production from photoelectrolysis of water due to its appropriate band gap, low cost and high electrochemical stability in aqueous caustic electrolytes. The operation of such photoanode in a biased photoelectrochemical cell constitutes an anodization with consequent redox reactions at the electrode surface. α-Fe2O3 thin film photoanodes were prepared by the Hydrothermal method and via Dr. Blade technic for a coating on fluorine-doped tin oxide (FTO) glass substrate, annealed in air at 500 ˚C for 2 hours. Changes in structural properties and morphology of α-Fe2O3 nanoparticles films were investigated by XRD, SEM. The UV-visible measurements revealed enhanced absorption in the photoanodes with optimized morphology. The findings suggest that optimized morphology causes only changes of the molecular structure at the surface and not in the crystallographic structure which can be detected with x-ray diffractometry.

Keywords:

Hematite , Photoanode , Solar water splitting , Morphology