Synthesis and photocatalytic oxidation of different organic dyes by using Mn2O3/TiO2 solid solution and visible light

Mn2O3/TiO2 solid solution was prepared from two different oxides, manganese oxide (from KMnO4 and ethanol) and TiO2, these samples were characterized by BET, XRD, EDAX, SEM, FT-IR, ESR, XPS and UV-vis absorption spectroscopy. Photocatalytic activities of Mn2O3/TiO2 powder was investigated by photooxidation of different dyes like Rhodamine B, thymol blue, methyl orange and Bromocresol green under visible light (300-W Xe lamp; lambda > 420 nm). The results show that the alloy of TiO2 with 1 mol% of Mn2O3 (MNT1) exhibit photocatalytic activity 3-5 times higher than that of P25 TiO2 for oxidation of various dyes (RB, TB, MO and BG). The average particle size and crystallite size of MNT1 were found to be 100 nm and 12 nm measured from SEM and XRD, respectively. The EPR spectra of the Mn2O3/TiO2 samples is a sharp five-line Mn(III) component centered on g(eff) = 1.99. (C) 2009 Published by Elsevier B. V.