Fabrication and utilization of ternary cubical nanostructure modified activated carbon cloth electrodes for capacitive deionization system

Cubical nanostructure zinc tin oxide (ZTO) was in-situ deposited on activated carbon cloth (ACC) substrate via a co-precipitation method. The amount and size of ZTO on the ACC substrate were varied by changing the different overall metal ion (Sn⁴⁺ and Zn²⁺) concentrations. The surface morphology and crystalline analysis revealed the well distributed cubic shape perovskite ZTO on the ACC substrates. The ZTO-deposited ACC electrodes showed superior electrochemical performances with higher specific capacitance and better ion transfer activity than pristine ACC. ZTO deposited ACC substrates were used as electrodes in a capacitive deionization system. ACC substrate coated with 0.01 M Sn and Zn metal concentrations achieved the best desalination efficiency of 52%, salt adsorption capacity of 45.0 ± 2 mg/g and faster salt adsorption rate of 0.14 mg/g/s compared to the other tested electrodes using 500 ppm NaCl solution. Further desalination of real groundwater (1000 ppm) achieved with ions adsorption improvement of 36% for Na⁺, 48% for Ca²⁺, 60% for Mg²⁺, and 46% for Cl^- compared to the pristine ACC. Additionally, compared to the pristine ACC, the ZTO-coated electrode enhanced the ions adsorption rate and reduced energy consumption by 40%. Post surface characterization of used pristine ACC displayed substantial scaling of the minerals from the ground water but ZTO-II electrodes exhibited better stability with less scaling. The outcomes of this study provide a stepping stone for the modification and utilization of electrodes for the real brackish water in the CDI system.