Preparation and photocatalytic properties of Cr/Ti hollow spheres

Cr/Ti hollow spheres were prepared using poly-(styrene-methyl acrylic acid) latex particles as a template. The photodecomposition of the methylene blue (MB) was evaluated on these Cr/Ti hollow spheres under visible light irradiation. The catalyst samples were characterized by XRD, TEM, UV-DRS, SEM, and BET, and the prepared sample was obtained with the formation of predominant rutile. The observation from UV-DRS showed that the increase of Cr3+ contents shifted the light absorption of the specimens to the visible region. In this study, the 0.5% Cr/Ti hollow sphere exhibited the highest MB photodecomposition. The BET surface area was found to be ∼25.5 m2 g−1 for the 0.5% Cr/Ti hollow sphere. The modification of the TiO2 surface by chromium ion improved the photocatalytic activity under visible light.