Capacitive deionization (CDI) is one of the most efficient and emerging techniques for water desalination applications. This work reports the development, characterization and CDI studies of watermelon derived activated carbon (WMAC) and its MnFe₂O₄ composite (WMAC/MnFe₂O₄) for NaCl desalination. WMAC was prepared through single-step low-temperature pyrolysis by H₃PO₄ activation. Facile synthesis of spinel MnFe₂O₄ nanoparticles on WMAC surface was performed through the hydrothermal technique. Morphological, textural and physico/electro–chemical analysis showed the effect of MnFe₂O₄ incorporation on WMAC. The nanocomposite possessed definite crystallites, low structural disorders and sufficient magnetization for electrochemical applications. Also, the nanocomposite was dominantly composed of mesopores with a specific surface area of 483 m²/g., The high specific capacitance value of 425 F/g (scan rate – 10 mV/s) along with better stability and low charge resistance, confirmed the suitability of WMAC/MnFe₂O₄ as an efficient electrode material for CDI applications. NaCl removal studies using WMAC/MnFe₂O₄ showed an electrosorption capacity of 29 mg/g for the nanocomposite, with rapid desalination and good recyclability. A plausible mechanism of salt adsorption and desorption is also presented. WMAC/MnF₂O₄ exhibited significant application potential for the industrial desalination.

电容去离子（CDI）是用于水脱盐应用的最有效和新兴的技术之一。这项工作报告了西瓜衍生的活性炭（WMAC）及其用于NaCl脱盐的MnFe ₂ O ₄复合材料（WMAC / MnFe ₂ O ₄）的开发，表征和CDI研究。WMAC是通过H ₃ PO ₄活化通过一步低温热解制备的。通过水热技术在WMAC表面方便地合成了尖晶石MnFe ₂ O ₄纳米颗粒。形态，结构和物理/电化学分析表明MnFe ₂ O _4的作用加入WMAC。该纳米复合材料具有确定的微晶，低结构紊乱和足够的磁化强度，可用于电化学应用。此外，纳米复合材料主要由比表面积为483 m ² / g的中孔组成，比电容值为425 F / g（扫描速率– 10 mV / s），具有更高的稳定性和较低的抗充电性，证实了WMAC / MnFe ₂ O ₄作为CDI应用的有效电极材料的适用性。使用WMAC / MnFe ₂ O ₄去除NaCl的研究纳米复合材料的电吸附容量为29 mg / g，具有快速脱盐和良好的可回收性。还提出了合理的盐吸附和解吸机理。WMAC / MnF ₂ O ₄在工业脱盐方面显示出巨大的应用潜力。