Promotion effect of free Ag+ ions on photocatalytic dechlorination processes

Abstract

Free silver ions (Ag⁺) in the solution exhibit enhanced photocatalytic dechlorination processes of organic chloride, including 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP), over copper phenylacetylene (PhC₂Cu) under visible light irradiation. The concentration of AgNO₃ remarkably affects the dechlorination activity of PhC₂Cu. With the optimal concentration of 2 mM AgNO₃, PhC₂Cu showed the best photocatalytic performance, and the dechlorination rate of PhC₂Cu was 2.3-fold enhanced under visible light irradiation for 80 minutes. This deep mechanism study demonstrated that free Ag⁺ in the solution, but not the deposited Ag particles on the surface of PhC₂Cu, plays the most imported role in promoting the photocatalytic dechlorination process by forming the insoluble salt of AgCl.