(117z) Copper and Gallate MOF for Electrosorption of Cadmium Ions

There is a growing need for environmentally friendly technologies that can effectively remove toxic heavy metal ions from wastewater. This research showcases a novel approach to electrochemically remove and release cadmium ions (Cd²⁺) using a cost-effective and water-stable metal-organic framework (MOF) made of copper gallate (CuGA). The MOF was synthesized using naturally abundant gallic acid as a linker in an aqueous solution. The study utilized copper within the CuGA structure as a redox center to attract Cd²⁺ through Cu²⁺/Cu⁺ reduction, resulting in rapid uptake kinetics and a much higher capacity (> 60 mg g^-1) than without electrochemical assistance (~15 mg g^-1). Furthermore, the recovery of Cd²⁺ and the regeneration of the electrode were facilitated without the need for regenerants by applying an opposite overpotential to induce the re-oxidation of copper. Physicochemical characterizations, including XPS analysis, were conducted to investigate the electrode's chemical oxidation states and stability after the electrosorption-regeneration process. This work demonstrated the potential of a Cu-based MOF electrode as a reusable platform for efficient Cd²⁺ removal and supports further research and development of new Faradaic electrodes for electrochemical wastewater treatments.