Recovering Ag+ with nano-MOF-303 to form Ag/AgCl/MOF-303 photocatalyst: the role of stored Cl− ions

The nano-MOF-303 synthesized by microwave method exhibited efficient adsorption capacity (232 mg/g) toward Ag+, in which the adsorption behaviors were fitted by the pseudo-second-order kinetic and the Freundlich isotherm model. The outstanding Ag+ sorption ability of nano-MOF-303 could be contributed to electrostatic interactions, weak coordination interaction of Ag-N, and AgCl precipitates originating from the stored Cl− in nano-MOF-303. Besides the adsorbent regeneration, the formed Ag/AgCl onto nano-MOF-303 could produce Ag/AgCl/MOF-303 as a photocatalyst for sulfamethoxazole degradation under visible light. In this work, both the adsorption and photocatalysis mechanisms were clarified, which might provide insight to develop more effective adsorbents for mining the critical resource from the wastewater.