Synthesis, characterization and photocatalytic activity of new photocatalyst CdBiYO_4

摘要

CdBiYO_4 was synthesized by a solid-state reaction method for the first time. The structural and photo-catalytic properties of CdBiYO_4 had been characterized by X-ray diffraction, scanning electron microscopy. X-ray photoelectron spectroscopy and X-ray spectrometry. CdBiYO_4 crystallized with a tetragonal spinel structure by space group I41/amd. The lattice parameters for CdBiYO_4 were a = b = 14.519 A and c = 9.442 A. The band gap of CdBiYO_4 was estimated to be 2.41 eV. The photocatalytic degradation of methylene blue (MB) was realized under visible light irradiation with CdBiYO_4 as catalyst. The results showed that CdBiYO_4 owned higher photocatalytic activity compared with pure TiO_2 or N-doped TiO_2 for photocatalytic degradation of MB under visible light irradiation. The photocatalytic degradation of MB with CdBiYO_4 or N-doped TiO_2 as catalyst followed the first-order reaction kinetics, and the first-order rate constant was 0.0137 or 0.0033 min~(-1). After visible light irradiation for 225 min with CdBiY04 as catalyst, complete removal and mineralization of MB were observed. The reduction of the total organic carbon, the formation of inorganic products, SO_4~(2-) and NO_3~-, and the evolution of CO_2 revealed the continuous mineralization of MB during the photocatalytic process. The possible photocatalytic degradation pathway of MB was obtained under visible light irradiation. CdBiYO_4/(visible light) photocatalysis system was found to be suitable for textile industry wastewater treatment and could be utilized to resolve other environmental chemical pollution problems.