Facet-dependent Performance Of Zn O Nanocrystal For Adsorption Of U(?)

The structure,morphology,crystal surface and surface characteristics of the samples were systematically analyzed by XRD,SEM,TEM and BET.The results showed that the rod-shaped self-assembled ZnO,its the specific surface area is 14.57m2 g^-1,mainly exposed the non-polar?100?crystal surface,while the lamellar self-assembled ZnO,its the specific surface area is 36.56m2 g^-1,mainly exposed the polar?001?crystal surface.After the successful preparation of the required structure of ZnO,the adsorption properties of ZnO on uranium ions???were compared and determined.The adsorption thermodynamics and kinetics characteristics were analyzed.The concentration of dissolved Zn2+ ions in the solution was determined.The main conclusions are as follows: when uranium concentration is C₀=50mg l^-1,saturated adsorption capacity is 75.1 mg g^-1,and when uranium concentration is C₀=500 mg l^-1,saturated adsorption capacity is 920.75 mg g^-1.The adsorption process of rod-like self-assembled nano-structure ZnO conforms to the quasi-second-order kinetic model?R²=0.99?and the Langmuir adsorption isothermalequation?R²=0.873?,indicating that it is a chemical adsorption process.The dissolution amount of Zn?II?in solution with different adsorption time was determined by ICP-MS,and the order of uranium adsorption performance from high to low was?100?>?001?in combination with the structural differences of the two crystal surfaces and their adsorption performance for uranium???.This activity difference may be due to the density and arrangement of zinc atoms on different crystal surfaces.