磁性Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)Z型异质结的制备及光催化降解性能

Magnetic Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4) Z-scheme Heterojunction:Preparation and Its Photocatalytic Degradation Property

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_(1.95)Sm_(0.05)O_(4)作为载体,通过原位沉积法和光还原法制备了Z型异质结Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4),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。Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)复合物催化活性最高,其光催化降解动力学常数(k)分别是Ag_(2)S/Ag,Ag_(2)S和CoFe_(1.95)Sm_(0.05)O_(4)的2.96, 3.71和8.24倍。引入CoFe_(1.95)Sm_(0.05)O_(4)可以有效地促进Ag_(2)S/Ag中光生载流子的分离效率。·O_(2)^(-)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Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)复合材料快速从溶液中分离出来。循环降解实验显示, Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)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_(1.95)Sm_(0.05)O_(4)as a support,the Z-scheme heterojunction Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)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. Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)composite exhibited the highest catalytic activity, which dynamic constant(k)was 1.96, 2.71 and 7.24 times higher than those of Ag_(2)S/Ag, Ag_(2)S and CoFe_(1.95)Sm_(0.05)O_(4), respectively. Introduction of CoFe_(1.95)Sm_(0.05)O_(4)could efficiently promote the separation efficiency of photogenerated charge carriers in Ag_(2)S/Ag. And ·O_(2)^(-)and ·OH^(-)were proved to be the main active substances in the photocatalytic process. In addition,the as-prepared Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)composite could be quickly separated from the solution by an extra magnetic field after the photocatalytic reaction. Cyclic photodegradation test showed that the Ag_(2)S/Ag/CoFe_(1.95)Sm_(0.05)O_(4)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.