Synthesis and Analysis of In2CdO4/Y2SmSbO7 Nanocomposite for the Photocatalytic Degradation of Rhodamine B within Dye Wastewater under Visible Light Irradiation

A new photocatalyst In2CdO4 was prepared by a solid phase sintering synthesis method at high temperature for the first time in this paper. The In2CdO4/Y2SmSbO7 heterojunction (IYH) catalyst was prepared by the solvent thermal method for the first time. The Y2SmSbO7 compound crystallized in the pyrochlore-type architecture and cubelike crystal system, and the space group of Y2SmSbO7 was Fd3m and the crystal cell parameters of Y2SmSbO7 was 9.51349 Å. The band gap width of Y2SmSbO7 was 2.63 eV. In2CdO4 crystallized with a body centered tetragonal lattice structure which was a tetragonal crystal system with a space group of I41/amd. The band gap width of In2CdO4 was 2.70 eV. After 110 minutes of visible light irradiation (VLGI-110min) with IYH as the photocatalyst, the removal rate (RR) of rhodamine B (RhB) concentration was 100% and the total organic carbon (TOC) concentration RR was 99.71%. The power mechanics invariable k toward RhB consistency and visible light irradiation (VLGI) time with IYH as the photocatalyzer reached 0.03073 min−1. The power mechanics invariable k which was involved with TOC reached 0.03621 min−1. After VLGI-110min, the RR of RhB with IYH as the photocatalyzer was 1.094, 1.174 or 1.740 times higher than that with In2CdO4, Y2SmSbO7 or N-doping TiO2 (N-TO) as the photocatalyzer, respectively. The results showed that the photocatalytic activity of IYH was the highest compared with In2CdO4, Y2SmSbO7, or N-TO. With appending a trapping agent, the oxidative capability for degrading RhB, which ranged from strong to weak among three oxidative radical groups, was as follows: hydroxyl radicals > superoxide anion > holes. This work provided a scientific basis for the research which resulted in prosperous development of efficient heterojunction compound catalysts.