Simultaneous Separation and Recovery of Gold and Copper from Electronic Waste Enabled by an Asymmetric Electrochemical System.

Exploiting efficient strategies for the selective separation and extraction of valuable metals from e-waste is in urgent demand to offset the ever-increasing depletion of metal resources, satisfy the sustainable supply of metal resources, and reduce the environmental impact from toxic metals. Herein, an asymmetric electrochemical system, constructed by polyaniline (PANI) nanofibers grown on carbon cloth (CC) and CC as the respective counter and working electrodes, is presented for the simultaneous and selective extraction of gold and copper from e-waste leachate solution. Harnessing the established CC/PANI//CC system, CC/PANI as the anode electrode is capable of selectively and rapidly extracting gold with high efficiency, accompanied by excellent reusability. Meanwhile, cathodic CC electrode is found to achieve almost 100% recovery of copper at a voltage of -1.2 V. Furthermore, the feasibility of the proposed asymmetric electrochemical system is further exemplified in waste central processing unit (CPU) leaching solution, enabling to recover simultaneously gold and copper with high purity. This work will provide meaningful guidance for simultaneous separation and recovery of multiple valuable metals from real e-waste.