Photophysical and photocatalytic properties of novel Y2GaSbO7 and Y2YbSbO7 photocatalysts under visible light irradiation

Abstract

Y2GaSbO7 and Y2YbSbO7 were synthesized by solid state reaction method for the first time. The crystallinity, composition, bandgap, morphology, and grain size of Y2GaSbO7 and Y2YbSbO7 were characterized by a series of analytical techniques. The lattice parameter a for Y2GaSbO7 was found to be 10.17981(1) A, and the lattice parameters for Y2YbSbO7 were found to be a = 10.49741(9) A, b = 7.45088(3) A, c = 7.47148(7) A, respectively. The values of band gap for Y2GaSbO7 and Y2YbSbO7 were calculated to be 2.245 and 2.521 eV, respectively. The photocatalytic degradation of rhodamine B (RhB) with Y2GaSbO7 or Y2YbSbO7 as photocatalyst was investigated under visible light irradiation. The results showed that Y2GaSbO7 and Y2YbSbO7 owned higher photocatalytic activity compared with Bi2InTaO7. Moreover, Y2GaSbO7 showed higher photocatalytic activity compared with Y2YbSbO7 for the photocatalytic degradation of RhB. The photocatalytic degradation of RhB followed the first-order reaction kinetics. The first-order rate constant, k, was 0.01817, 0.01341, and 0.00329 min−1 for Y2GaSbO7, Y2YbSbO7, and Bi2InTaO7, respectively. Complete removal of RhB was realized after visible light irradiation for 220 or 240 min with Y2GaSbO7 or Y2YbSbO7 as photocatalyst. The reduction of the total organic carbon and the evolution of CO2 were also realized and these results indicated the continuous mineralization of RhB during the photocatalytic process with Y2GaSbO7 or Y2YbSbO7 as photocatalyst. The possible photocatalytic degradation pathway of RhB was revealed under visible light irradiation. Methylene blue and neutral red could be degraded efficiently with Y2GaSbO7 or Y2YbSbO7 as photocatalyst under visible light irradiation.