Structural characteristics of mixed oxides MOx/SiO2 affecting photocatalytic decomposition of methylene blue

► Thermal treatment of SiO2/TiO2 mixed oxides result in separation of the SiO2 and TiO2 phases providing an increased TiO2 anatase crystalline phase content. ► The increased anatase content after thermal treatment is correlated with the increased photocatalytic degradation ability of these materials with the organic dye methylene blue. ► The photocatalytic degradation ability did not directly correlate with properties other than crystallinity for any of the mixed oxides studied (CeO2/SiO2, CeO2, ZrO2/CeO2/SiO2, TiO2/Fe2O3/SiO2). These properties included surface area, particle size, zeta potential, surface charge density, and calculated band gap energy.