Photocatalytic decomposition of methyl orange over nanosized perovskite-type oxides under visible light irradiation.

In this study, we have investigated the photocatalytic activity for the decomposition of methyl orange on the LaCoO3 perovskite-type oxides prepared using sol-gel method at different conditions. From the results of UV-Vis DRS, all the catalysts have the similar absorption spectrum up to visible region. The LaCoO3 catalyst prepared at 1.5 mol of malic acid and calcined at 350 degrees C shows the highest activity. The amount of photo absorption in the visible region is correlated with the photocatalytic activity. In addition, the chemisorbed oxygen plays an important role on the photocatalytic decomposition of methyl orange and the higher are the contents of chemisorbed oxygen, the better shows the performance of photocatalyst.