Novel LaBO3 hollow nanospheres of size 34±2 nm templated by polymeric micelles.

Abstract Novel lanthanum borate (LaBO 3 ) hollow nanospheres of size 34 ± 2 nm have been reported for the first time by soft-template self-assembly process. Poly(styrene- b -acrylic acid- b -ethylene oxide) (PS-PAA-PEO) micelle with core – shell – corona architecture serves as an efficient soft template for fabrication of LaBO 3 hollow particles using sodium borohydride (NaBH 4 ) and LaCl 3 ⋅7H 2 O as the precursors. In this template, the PS block ( core ) acts as a template of the void space of hollow particle, the anionic PAA block ( shell ) serves as reaction field for metal ion interactions, and the PEO block ( corona ) stabilizes the polymer/lanthana composite particles. The PS-PAA-PEO micelles and the resulting LaBO 3 hollow nanospheres were thoroughly characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), X-ray diffraction, magic angle spinning-nuclear magnetic resonance ( 11 B MAS NMR), energy dispersive X-ray analysis, thermal analyses, Fourier transform infra red spectroscopy, and nitrogen adsorption/desorption analyses. The nitrogen adsorption/desorption analyses and TEM observation of the hollow particles confirmed the presence of disordered mesopores in the LaBO 3 shell domain. The solid state 11 B MAS NMR spectra of LaBO 3 hollow nanospheres revealed that the shell part contains both trigonal and tetrahedral boron species. The LaBO 3 hollow particles were applied to anode materials in lithium-ion rechargeable batteries (LIBs). The hollow particles exhibited high coulombic efficiency and charge–discharge cycling capacities of up to 100 cycles in the LIBs.