Acta Phys. -Chim. Sin. ›› 2026, Vol. 42 ›› Issue (10): 100330.doi: 10.1016/j.actphy.2026.100330

• ARTICLE • Previous Articles     Next Articles

Maximizing the phosphate adsorption capacity of layered double hydroxides in asymmetric electrochemical deionization systems

Ziquan Wang, Zhujie Liang, Xing Liu, Yihuang Lin, Jiangluo Liu, Zengye Chen, Libo Deng*()   

  1. College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, Guangdong Province, China
  • Received:2026-03-30 Revised:2026-05-18 Accepted:2026-05-24 Published:2026-09-03
  • Contact: Email: Denglb@szu.edu.cn (Libo Deng)

Abstract:

Uncontrolled discharge of phosphate-containing wastewater causes severe aquatic eutrophication, posing a critical challenge to global water security. Electrochemical deionization (EDI) is a promising approach for phosphate removal, but its practical application is hindered by limited electrode capacity and capacity mismatch in asymmetric systems. Herein, cubic CoFe-layered double hydroxide (LDH) and nanospike coaxial CoAl LDH were in-situ grown on conductive carbon cloth (CC) via a one-step hydrothermal method as freestanding anodes for asymmetric EDI systems. The CoAl LDH electrode exhibits superior electrochemical performance and phosphate adsorption capacity compared to CoFe LDH, owing to its unique hierarchical structure and crystal structure that enables faster ion transport kinetics and richer active sites. By optimizing the cathode/anode mass ratio to 2 : 1, the capacity mismatch issue of the asymmetric system is effectively mitigated, and the optimized EDI system with CoAl LDH/CC anode delivers a high phosphate adsorption capacity of 41.9 mg P g−1 at 1.2 V, along with excellent long-term stability (87% capacity retention after 120 h continuous operation). This work provides valuable insights for the development of high-performance EDI systems for phosphate removal.

Key words: Phosphate removal, Electrochemical deionization, Layered double hydroxide, Freestanding electrode