Synthesis and catalytic activity of new Gd2BiSbO7 and Gd2YSbO7 nanocatalysts

Cd2BiSbO7 and Gd2YSbO7 were prepared for the first time and the structural and photocatalytic properties of Gd2BiSbO7 and Gd2YSbO7 were investigated. The results showed that Gd2BiSbO7 and Gd2YSbO7 crystallized with the pyrochlore-type structure, cubic crystal system by space group Fd3m. The lattice parameters a for Gd2BiSbO7 and Gd2YSbO7 were 10.70352(7) and 10.65365(1) angstrom, respectively. The band gaps of Gd2BiSbO7 and Gd2YSbO7 were estimated to be 2.081 and 2.396 eV, respectively. The photocatalytic degradation of rhodamine B (RhB) over Gd2BiSbO7 and Gd2YSbO7 was investigated under visible light irradiation. The results showed that Gd2YSbO7 and Gd2BiSbO7 owned higher catalytic activity compared with Bi2InTaO7. Moreover, Gd2YSbO7 showed higher catalytic activity compared with Gd2BiSbO7 for RhB photocatalytic degradation. The photocatalytic RhB degradation followed the first-order reaction kinetics, the apparent first-order rate constant k being 0.01766, 0.01906 and 0.00318 mid(-1) with Gd2BiSbO7. Gd2YSbO7 and Bi2InTaO7, respectively. Complete removal of RhB was realized after visible light irradiation for 230 and 240 min with Gd2YSbO7 and Gd2BiSbO7. The reduction of the total organic carbon and the evolution of CO2 revealed complete removal of RhB during the photocatalytic process by Gd2YSbO7 and Gd2BiSbO7. The possible photocatalytic degradation pathway of RhB was revealed under visible light irradiation. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.