Regulator-induced defective functionalization of MOFs: Efficient recovery of gold ions from wastewater

Given the scarcity of precious metals in nature and the high costs of extraction and refinement, their recovery holds significant practical importance. In this study, we employed an induced-defect strategy to prepare a novel metal-organic framework material, UiO-67-MAA, using a one-step solvent method that exhibited rapid adsorption kinetics and ultra-high adsorption capacity. In addition, the ability of the material to recover Au(III) from aqueous solutions was evaluated through systematic adsorption experiments. Various characterisation methods were employed to verify the successful synthesis and structural stability of UiO-67-MAA. The maximum adsorption capacity of UiO-67-MAA for Au(III) reaches 814 mg/g. In repeated experiments, the removal effect of UiO-67-MAA on Au(III) remained significant even after five cycles. The adsorption mechanism was analysed by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS), confirming that S atoms interact with Au(III) to form a stable coordination structure. These results indicate that UiO-67-MAA possesses efficient adsorption properties for Au(III), thus demonstrating its significant potential for application in precious metal recovery.