Effect of high energy ball milling on the physicochemical properties of TiO <inf>2</inf> –CeO <inf>2</inf> mixed oxide and its photocatalytic behavior in the oxidation reaction

Abstract

TiO 2 –CeO 2 photocatalysts were synthesized by a high energy ball milling process at different milling speed and their photocatalytic activities were evaluated by measuring degradation efficiency of methyl orange. Phases, crystal size, microstrain, and morphology were evaluated. The results have demonstrated that the milling reduces the average crystallite size for any milling speed. Increasing speed leads to the sticking of small particles to form strong and porous agglomerates with a lower specific surface area. XRD analysis shows that the enhanced milling speed affects pronounced anatase-to-rutile phase transformation. All of these changes influence the photocatalytic activity that is decreased by milling speed increase. Role of CeO 2 in the TiO 2 –CeO 2 photocatalytic system is to prolong life of electron/hole pair formed by the interaction of light with TiO 2 .