Rerouting Charge Transfer for Pharmaceutical Wastewater Electrochemical Treatment via Interfacial Cocatalyst Modification

Abstract

Electrochemical oxidation stands as a pivotal technology for refractory wastewater treatment. However, the high cost and low elemental abundance of commercial electrodes limit its widespread application. This work tries to address this by introducing a charge-transfer rerouting strategy via cocatalyst modification using earth-abundant elements. Here, we uncover the role of the cocatalyst in enhancing electrode performance. The in-situ reconstructed cocatalyst induces a substantial rerouting of the charge transfer pathway, facilitating the mass/charge transfer of organics while concurrently suppressing the oxygen evolution side reaction. The Ti-Fe₂O₃ electrode, loaded with the cocatalyst PbO₂, exhibits both high current efficiency (~45.4%) and low energy requirement (~31.8 kW h kg^-1 COD), surpassing other reported electrodes and displaying great versatility in various scenarios with good stability and reusability. Moreover, this charge-transfer rerouting strategy holds promise for synergy with other methodologies, such as nanostructure engineering and molecular imprinting, to further enhance the reactivity and selectivity of electrocatalysts in environment and energy-related domains.