光催化降解水体中的有机污染物具有广阔的应用前景。本研究以CoFe_1.95Sm_0.05O₄作为载体, 通过原位沉积法和光还原法制备了Z型异质结Ag₂S/Ag/CoFe_1.95Sm_0.05O₄, 采用不同表征手段对样品的微观形貌、物相结构、光学和磁学性能进行表征分析。Ag₂S/Ag/CoFe_1.95Sm_0.05O₄复合物催化活性最高, 其光催化降解动力学常数(k)分别是Ag₂S/Ag, Ag₂S和CoFe_1.95Sm_0.05O₄的2.96, 3.71和8.24倍。引入CoFe_1.95Sm_0.05O₄可以有效地促进Ag₂S/Ag中光生载流子的分离效率。?O₂^-和 ?OH^-是光催化过程中的主要活性物。此外, 在光催化反应后, 外加磁场可以将制备的Ag₂S/Ag/CoFe_1.95Sm_0.05O₄复合材料快速从溶液中分离出来。循环降解实验显示, Ag₂S/Ag/CoFe_1.95Sm_0.05O₄复合材料在光降解过程中具有稳定的降解能力和晶体结构。本研究为进一步开发高效、窄带隙和磁性的光催化剂提供了有效的解决思路。

Photocatalytic degradation of organic pollutants from water bodies can efficiently reduce the organic pollutants in wastewater, which has broad application prospects. In this study, using CoFe_1.95Sm_0.05O₄ as a support, the Z-scheme heterojunction Ag₂S/Ag/CoFe_1.95Sm_0.05O₄ was synthesized through a facile in situ deposition method followed by photo-reduction. Microstructure, phase structure, optical and magnetic properties of the samples were analyzed. Ag₂S/Ag/CoFe_1.95Sm_0.05O₄ composite exhibited the highest catalytic activity, which dynamic constant (k) was 1.96, 2.71 and 7.24 times higher than those of Ag₂S/Ag, Ag₂S and CoFe_1.95Sm_0.05O₄, respectively. Introduction of CoFe_1.95Sm_0.05O₄ could ef?ciently promote the separation ef?ciency of photogenerated charge carriers in Ag₂S/Ag. And ?O₂^-and ?OH^- were proved to be the main active substances in the photocatalytic process. In addition, the as-prepared Ag₂S/Ag/CoFe_1.95Sm_0.05O₄ composite could be quickly separated from the solution by an extra magnetic field after the photocatalytic reaction. Cyclic photodegradation test showed that the Ag₂S/Ag/CoFe_1.95Sm_0.05O₄ hybrid materials had the stable degradation ability and crystal structures in the photodegradation process. This research provides a useful approach to develop photocatalysts with high efficiency, narrow band gap and magnetism.