Preparation of AgCl photocatalyst by recovering silver from discarded cyanide-free silver electrodeposition bath: insightful investigation of quantum chemical calculations and experiment

The recovery of silver from cyanide-free silver electrodeposition bath to prepare AgCl photocatalyst was studied by quantum chemical calculations and experiment. Quantum chemical calculations were used to predict the coordinated bonds broken mechanism as well as silver recovery and AgCl photocatalyst formation. Based on the prediction, HCl was used in silver recovery and preparation of AgCl. With addition of HCl into silver electrodeposition bath, coordinated bonds between Ag ⁺ and composite complexing agents, 5,5-dimethylhydantoin (DMH) and nicotinic acid (NA), were broken and the Ag ⁺ was recovered as AgCl with high purity. The composition of products was studied byXRD and XPS measurements. The introduced method is effective and economical for silver recovery from investigated bath and wastewaters. The insight view of coordination interaction of complexing agents for metal ions in this manuscript is a great strength to perfect the investigation of novel metal recovery and resources recycling in aspect of technique and mechanism.