Engineering tunable oxygen vacancies in Mn3O4 for high-performance capacitive deionization

Mn₃O₄ electrodes were synthesized via a facile amino acid-assisted method. • The optimized electrode delivers ultrahigh electrosorption capacity and rate. • The system demonstrates a low energy consumption with negligible manganese leaching, ensuring safe and sustainable operation. To address the limitations in ion adsorption capacity and kinetics of conventional capacitive deionization (CDI) systems, this study proposes the utilization of Mn 3 O 4 electrodes featuring tailored oxygen vacancy to enhance desalination performance. Mn 3 O 4 materials with tunable oxygen vacancy concentrations were synthesized via an amino acid-assisted method and employed as CDI anodes. The introduced oxygen vacancies significantly improved the electrode's electrosorption capacity and reaction kinetics. The optimized electrode exhibited an electrosorption capacity of 110 mg/g at 1.2 V and an average salt removal rate of 29.26 mg/g/min. Compared with conventional electro-driven desalination technologies, the developed system demonstrates lower energy consumption while maintaining operational flexibility, offering a promising material and process strategy toward efficient and sustainable desalination.