The synthesis and characterization of AlPO4 hollow microspheres of uniform size, and the sorption properties for Pb2+, Cd2+, Cu2+, and Zn2+

Abstract Well-defined aluminum phosphate hollow microspheres (AlPO 4 -HMs) of uniform size were synthesized via homogeneous precipitation using polystyrene (PS) as the template. The as-prepared AlPO 4 -HMs were characterized by FESEM, TEM, XRD, FTIR and N 2 adsorption/desorption. The adsorption of AlPO 4 -HMs towards Pb 2+ , Cd 2+ , Cu 2+ and Zn 2+ metal ions was also studied. The FESEM and TEM images show that the AlPO 4 -HMs display a regular spherical hollow structure that is about 250 nm in size, and have a special and superior sorption performance for Pb 2+ adsorption from aqueous solution compared with the Cd 2+ , Cu 2+ , Zn 2+ metal ions. The adsorption of Pb 2+ ions follows the Langmuir isotherm and the Pseudo-second-order kinetic equation as well as the intra-particle diffusion model.