Hierarchical Hydroxyapatite Microspheres Composed of Nanorods and Their Competitive Sorption Behavior for Heavy Metal Ions

Hydroxyapatite (HAP) microspheres composed of nanorods have successfully been prepared by a facile co‐precipitation method without any template. We propose the formation mechanism of the microspheres to be a four‐step process on the basis of the evolution of their morphology as a function of reaction time. We investigate the competitive sorption of the HAP microspheres for Pb2+, Cu2+, Cd2+, Zn2+, and Ni2+ to show that HAP microspheres are a highly selective adsorbent for Pb2+ in wastewater. Hierarchically structured microspheres self‐assembled from hydroxyapatite nanorods have successfully been prepared by a simple co‐precipitation method without any template. The as‐prepared materials exhibit high selective adsorption for Pb2+ in wastewater.