Surface Acid-Base Property of Nano-Zns Particles and Adsorption Behavior of Pb²+ and Cu²+

Zinc sulfide nanoparticles were prepared by hydrothermal method and characterized by TEM, FT-IR and BET surface area. The titration results show that the surface of ZnS nanoparticles possessed an obvious acid-base property. With increasing the amount of ZnS nanoparticles in the suspension, the pH buffer capacity of solution increased dramatically. There is a proportional relationship between the amount of ZnS nanoparticles added and the solution pH buffer capacity. The adsorption conditions of Pb²⁺ and Cu²⁺ by ZnS nanoparticles was also optimized. They were: titration time of 1.0 h, the amount of ZnS nanoparticles added of 0.1846 g and solution pH of 6.7 for Pb²⁺ adsorption. For Cu²⁺, the conditions were 1.0 h, 0.1800 g and pH 6.5-7.0, respectively. The optimized pH values of Pb²⁺ and Cu²⁺ adsorption by ZnS nanoparticles were tested by the calculation of MEDUSA software.