Photoelectrocatalytic activity of ferric oxide nanocatalyst: A synergestic effect of thickness

The Fe2O3 thin films have been deposited using ferric trichloride precursor at an optimized substrate temperature and concentration by simple chemical spray pyrolysis technique. Effect of quantity of the spraying solution on physicochemical properties of Fe2O3 thin films has been studied. Photoelectrochemical technique was used to optimize the quantity of a spraying solution. The PEC study shows that, Fe2O3 films are photoactive with relatively higher values of Isc=34.2 μA and Voc=190 mV respectively at 50 ml quantity (thickness ~239 nm). Effects of thickness on crystalline structure, morphology and optical properties have been studied. X-ray diffraction study confirms that the films are polycrystalline with rhombohedral crystal structure. The SEM and AFM micrographs depicts that the films are compact and needle shaped grains with grain size ~160–250 nm. The direct band gap energy of Fe2O3 thin films is found to be in the range of 2.16–2.47 eV. Four characteristic luminescence peaks having near band-edge, violet, blue and green emission are observed in the photoluminescence spectra. Photocatalytic degradation of benzoic acid by using Fe2O3 photoelectrode under visible light illumination has been investigated. The amount of mineralization is confirmed by COD and TOC analysis.