Facile shape-controlled synthesis of lanthanum oxide with different hierarchical micro/nanostructures for antibacterial activity based on phosphate removal

In this study, three La2O3 hierarchical micro/nanostructures, nanospindles, nanopolyhedra and nanospheres, were synthesized to remove phosphate from microbial growth media for bacterial inactivation as an antimicrobial strategy. The experiment results showed that the morphology of La2O3 hierarchical micro/nanostructures can be controlled by the concentration of the reactants, reaction temperature and cooling treatment. Meanwhile, the properties of the La2O3 were researched for phosphate removal and antibacterial activity. The results showed that the different morphologies of the La2O3 micro/nanostructures had different removal abilities for phosphate, and can differently inhibit growth of bacteria. Spherical La2O3 possesses the best removal ability and antibacterial activity, which indicates that the smaller the La2O3 hierarchical micro/nanoparticles are, the stronger the phosphate removal capacity. Compared with nanoparticles, the hierarchical micro/nanoparticles have a significant advantage: they not only have the properties of nanoparticles, but also are relatively stable, not easy to aggregate, and are easy to separate after the reaction. Therefore, the La2O3 hierarchical micro-nanomaterials may have very good application prospects for phosphate reduction in open water and to inhibit algae overgrowth.