Zinc Spinel Ferrite Nanoparticles as Pseudocapacitive Electrode with Ultrahigh Desalination Capacity and Long-term Stability

The hybrid capacitive deionization configuration is a significant branch of CDI for the desalination of brackish water, which can be used to solve the worldwide freshwater shortage. Apart from traditional carbon-based electrodes, new electrode materials with low cost and high desalination capacity are key factors in the large-scale application of capacitive deionization technology. In this study, a novel zinc spinel ferrite nanoflake electrode was fabricated and applied for the first time in CDI. The electrode achieved excellent performance with ultrahigh desalination capacity and long-term stability and without the need for any modifications, such as carbon coating. The desalination capacity reaches 136.6 mg NaCl/g ZFO (zinc spinel ferrite) under optimized conditions with a current density of 30 mA/g, voltage range of -1.4 ~ 1.4 V and initial concentration of 100 mM. Moreover, the CDI system is stable for 200 cycles over a duration of more than 10 days. The excellent long-cycle performance reveals that Z...