Catalytic Activation Coupled Regulation of Carbon Structural Domains Enhances the Performance of Capacitive Deionization Purification of Cu 2+

Abstract The efficient purification of Cu 2+ ‐contaminated wastewater poses a formidable challenge. Capacitive deionization (CDI) technology, which operates on the principle of electrochemical capacitance, has emerged as a promising candidate for serving as a key technology to address this problem. In this work, chitosan is employed as a carbon precursor for the fabrication of a CDI carbon electrode (CoZn‐C). This electrode features a high specific surface area and short‐range ordered carbon domains, which are achieved through the strategic utilization of basic carbonate templates to induce site‐occupying effects, coupled with the synergistic catalysis of metal. Importantly, benefiting from sufficient electrochemical adsorption active sites and the carbon structural channels that facilitate rapid Cu 2+ transport, the constructed symmetric CoZn‐C//CoZn‐C CDI device demonstrates excellent purification capability for Cu 2+ . The adsorption capacity and removal efficiency of the CDI electrode for Cu 2+ are as high as 124.3 mg g −1 and 94.5%, respectively (at 1.2 V, 50 mg L −1 ). The electrochemical capture of Cu 2+ by CoZn‐C CDI electrodes is achieved through the coupling effect of the electrical double layer and electro‐reduction deposition. Accordingly, the carbon domain regulation method offers a new strategy for designing and constructing high‐efficiency CDI carbon electrodes for the heavy metal ion wastewater purification.