Asymmetric Capacitive Deionization Enhanced Removal of Fluoride by Zirconium Titanium Bimetallic/Biomass Carbon: A Low‐Cost Engineering Exploration Study

ABSTRACT With the development of industry, fluoride pollution has become increasingly severe. Transition metal phosphides, featuring excellent electrical conductivity and electrochemical stability, are promising electrode materials for capacitive deionization (CDI). In this study, an interface engineering strategy was proposed to anchor ZrP x nanoparticles onto the activated cattail biochar (AWC) skeleton and introduce TiO 2 as an electron transport bridge to construct ZrP x ‐AWC@TiO 2 anode materials for ternary composite materials and asymmetric CDI electroadsorption systems. It possesses a specific surface area of 39.52 m 2 g −1 , a specific capacitance of 8.46 F g −1 , and an adsorption capacity of 132.77 mg g −1 . The adsorption capacity of the asymmetric CDI system is 169.72 mg g −1 with ZrP, Zr 7 P 4 , TiO 2 , and ZrO 2 as the main electroadsorption sites. Fluoride in water is removed through chemical adsorption and hydrogen bonding. The higher adsorption energy calculated by density functional theory also indicates that the presence of Zr–P coordination bonds effectively enhances its electroadsorption ability. This study contributes to offering references and research insights for removing fluoride in the CDI domain.