Preparation of MoS2/TiO2/carbon ball electrodes for high-performance flow-electrode capacitive deionization device

Abstract

In this study, to increase the desalination efficiency of capacitive deionization systems, materials such as TiO₂ and MoS₂ were deposited on activated carbon balls (ACBs) through dynamic liquid-phase deposition. This deposition process increased the hydrophilicity and electrochemical properties of the electrodes. In addition, the synthesis concentration ratios of various precursors and catalysts were modulated to alter the ratios of the elements and the 1 T and 2H phases of MoS₂. The results indicated that, because of the porous nature of ACBs, TiO₂ and MoS₂ uniformly grew within the ACBs, effectively mitigating the uneven distribution of electric fields within the electrodes. At a 1 T to 2H phase ratio of 1:1, the synergistic effect of the composite material facilitated the rapid transport of electrolyte ions and electrons across the electrode surface, resulting in high electrochemical performance. Next, MoS₂/TiO₂/ACB electrodes were mixed with activated carbon to enhance the mobility of the flow electrodes, achieving a desalination efficiency of 68.65% and a desalination capacity of 40.3 mg/g. After 50 repeated desalination tests, a desalination retention rate of 95.2% was achieved. Taken together, these results confirm that MoS₂/TiO₂/ACB electrodes have a high seawater desalination efficiency and long-term stability, indicating their potential in water purification applications.