Materials Research Bulletin, Vol.47, No.3, 562-570, 2012
Deposition of nanostructured photocatalytic zinc ferrite films using solution precursor plasma spraying
Deposition of pure spinet phase, photocatalytic zinc ferrite films on SS-304 substrates by solution precursor plasma spraying (SPPS) has been demonstrated for the first time. Deposition parameters such as precursor solution pH, concentration, film thickness, plasma power and gun-substrate distance were found to control physico-chemical properties of the film, with respect to their crystallinity, phase purity, and morphology. Alkaline precursor conditions (7 < pH <= 10) were found to favor oxide film formation. The nanostructured films produced under optimized conditions, with 500 mM solution at pH similar to 8.0, yielded pure cubic phase ZnFe2O4 film. Very high/low precursor concentrations yielded mixed phase, less adherent, and highly inhomogeneous thin films. Desired spinel phase was achieved in as-deposited condition under appropriately controlled spray conditions and exhibited a band gap of similar to 1.9 eV. The highly porous nature of the films favored its photocatalytic performance as indicated by methylene blue de-coloration under solar radiation. These immobilized films display good potential for visible light photocatalytic applications. (C) 2012 Elsevier Ltd. All rights reserved.