采用水热合成法制备了纳米CoFe_1.95Y_0.05O₄尖晶石催化剂，在制备Ag₂S的过程中采用简单的化学方法制备了异质结Ag₂S/CoFe_1.95Y_0.05O₄复合光催化剂。利用X射线衍射仪（XRD）、紫外-可见漫反射光谱仪（UV-Vis DRS）、扫描电子显微镜（SEM）、振动样品磁强计（VSM）、高分辨率透射电镜（HRTEM）对所制备Ag₂S/CoFe_1.95Y_0.05O₄进行结构和形态的表征。在可见光照射下降解甲基橙（MO）水溶液，考察制备的光催化剂的光催化活性。结果表明，Ag₂S/CoFe_1.95Y_0.05O₄降解甲基橙水溶液的一级动力学常数分别是Ag₂S和CoFe_1.95Y_0.05O₄的2.87倍和4.39倍。此外，通过外加磁场可快速从溶液分离出Ag₂S/CoFe_1.95Y_0.05O₄复合材料。循环降解实验表明，Ag₂S/CoFe_1.95Y_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，可循环利用并高效降解有机污染物。

Nano CoFe_1.95Y_0.05O₄ spinel catalyst is prepared by using hydrothermal synthesis method, and then Ag₂S/CoFe_1.95Y_0.05O₄ composite photocatalyst for the formation of heterojunction is prepared by using a simple chemical method in the preparation of Ag₂S.The structure and morphology of Ag₂S/CoFe_1.95Y_0.05O₄ are characterized by means of spectral techniques such as powder X-ray diffraction (XRD), ultraviolet-visible diffuse reflection spectroscopy (UV-Vis DRS), scanning electron microscopy (SEM), vibration sample magnetometer (VSM), and high-resolution transmission electron microscopy (HRTEM).The photocatalytic activity of the prepared photocatalyst is evaluated through degrading methyl orange aqueous solution under the visible light irradiation.The results show that the first-order kinetic constant of Ag₂S/CoFe_1.95Y_0.05O₄ for degrading methyl orange aqueous solution is 2.87 and 4.39 times that of Ag₂S and CoFe_1.95Y_0.05O₄, respectively.In addition, Ag₂S/CoFe_1.95Y_0.05O₄ composites can be rapidly separated from the solution by using an external magnetic field.Cyclic degradation experiment shows that Ag₂S/CoFe_1.95Y_0.05O₄ composite has stable degradation ability and crystal structure during photodegradation, and can be recycled and degrade organic pollutants efficiently.