Direct Measurement\nof the Differential Capacitance\nof Deep Eutectic Solvents on Platinum and Glassy Carbon Electrodes

Differential capacitance is a crucial parameter that\nconnects the\nexperimental observation of electrical double-layer behavior with\ntheoretical models. However, the current number of reported differential\ncapacitance values for deep eutectic solvents remains limited, making\nit challenging to verify or refute existing models. In this study,\nwe systematically investigate the differential capacitance in deep\neutectic solvents using chronoamperometry. By comparing metal and\nglassy carbon electrodes across various liquid combinations and ion\nconcentrations, we observed a range of distinct capacitance characteristics.\nWhile some findings align with the existing mean-field model for ionic\nliquids, others clearly reflect the influence of electrode materials,\nwith certain cases resisting full explanation by current theoretical\nmodels. These results underscore the importance of selecting appropriate\nelectrode materials in experimental studies of such electrolytes and\nhighlight the need for further theoretical advancements in understanding\nthis complex liquid system.