Development and applications of Ru and Ce based iron oxides as photocatalysts

Abstract

This paper describes cerium and ruthenium oxides as catalysts in photo-degradation of Congo Red. Results show an alteration in the chemical properties and crystal structure as Ru or Ce are incorporated into the system. Ruthenium materials, are a mixture of carbonous iron oxides, Ru2O and Ru0 clusters and cerium catalysts are a distorted spinel ferrite. Diffuse Reflectance Spectroscopy reveals direct bandgaps of 2.03 and 2.46 eV for Ru and Ce materials respectively. The photo-oxidation of Congo red followed first-order kinetics (k = 3.3 × 10−3 mol·min−1) in the presence of Ru catalysts whereas cerium materials performed poorly (k = 0.7 × 10−3 mol·min−1). A DFT structural optimization was attempted for ruthenium catalysts involving a mixture of Fe(CH3COO)2, Ru2O and Ru07 but for Ce materials, an inverse spinel with CeFe2O4 composition is presented.