Retracted Article: One-pot synthesis of O-doped BN nanosheets as a capacitive deionization electrode for efficient removal of heavy metal ions from water

Abstract

O-Doped BN nanosheets with a thickness of 1.033 nm were prepared via the direct reaction of CuB₂₃ with NOCl at room temperature in ionic liquids. It had a large high specific surface area of 858 m² g⁻¹, and showed a high electrical conductivity of 34.3 S m⁻¹ and a good specific capacity of 187 F g⁻¹. Meanwhile, the obtained sample demonstrated excellent performance as the electrode material for capacitive deionization (CDI) to remove Cd²⁺ from water in a wide range of concentrations from 0.05 to 600 ppm with a maximum adsorption capacity of 2281 mg g⁻¹. It is attributed to its unique structural characteristics and the ability of its NO– groups to coordinate Cd²⁺ which promotes the electrosorption. More importantly, it exhibited outstanding capability for the total, rapid, and simultaneous removal of multiple metal ions (Zn²⁺, Cd²⁺, Pb²⁺, Ni²⁺, Co²⁺, Cu²⁺, Mg²⁺, Ca²⁺, Fe²⁺, Fe³⁺ and Na⁺) by CDI within 20 min. These results suggest promising applications of our BNO nanosheets for water purification and water-softening devices based on CDI.