The faradic asymmetric electrodes have recently attracted attention in capacitive deionization (CDI) because of their capability to remove both Na+ and Cl− ions from saline solution to meet the freshwater requirements. However, the fabrication of CDI electrodes that are high-performing and stable remains a challenge. In this work, an asymmetric electrode with highly stable CDIs has been fabricated by using reduced graphene oxide (RGO) as positive electrodes and spherical-like manganese dioxide nanoparticles decorated RGO sheets (MnO2/RGO) as negative electrodes to selectively capture salt ions from saline solution. MnO2/RGO electrodes exhibit a large specific capacitance of about 485 F g−1 at 10 mV s−1 in NaCl with lower internal resistance, which is significantly higher than that of recent electrode materials. Due to the superior specific capacitance and lower internal resistance behavior of MnO2/RGO electrodes, asymmetric CDI device has been assembled for the desalination of salt using saline water. Especially, MnO2/RGO//RGO-based asymmetric CDI device shows higher salt uptake capacity (SAC) of 52 mg g−1 with higher average salt adsorption capacity (ASAR) of 2.7 mg g−1 min−1 than recently reported electrode materials. Furthermore, the recycling studies indicate that MnO2/RGO//RGO electrodes are promising electrode materials for prolonged CDI operation. In summary, the studies confirmed that the MnO2/RGO system offers excellent potential for producing portable drinking water by capacitive deionization of seawater.
Research Abstract
Research Date
Research Department
Research Journal
Advanced Composites and Hybrid Materials
Research Member
Research Vol
6
Research Year
2023