Controlled synthesis of BaSO4@Zr(HPO4)2 core–shell nanomaterials with excellent adsorption properties for Pb2+ ions

BaSO₄@Zr(HPO₄)₂ nanomaterial was prepared by using H₂C₂O₄ as a complexant at 90 °C. The as-prepared samples were determined by a series of characterizations. The morphology of BaSO₄@Zr(HPO₄)₂ was nanoplate with size of 300nm-2μm. The core-shell structure has the following advantages: (1) Excellent monodispersity. (2) Higher utilization rate and adsorption performance. The samples were used to adsorb Pb²⁺ in water. The adsorption process and mechanism were studied using adsorption kinetics and isotherm models. The effects of pH, adsorption time, and initial concentration of Pb²⁺ were investigated. It is shown that the samples exhibit excellent adsorption performance, the maximum Pb²⁺ adsorption capacity can reach 231.3 mg g⁻¹. The adsorption performance for Pb²⁺ was stable at pH 5–9. The adsorption process of Pb²⁺ is mainly a chemical adsorption process uniformly covered by monolayer. After five adsorption-desorption experiments, the adsorption capacity of the four samples can still maintain 76.2 %–40.3 % of the first adsorption.