A sonochemical approach for the synthesis of thermally stable mesoporous microspheres of TiO2 for use as high performance anodes for Li-ion batteries

A facile, surfactant-free sonochemical synthesis route at a relatively low temperature was employed to prepare mesoporous microspheres of anatase titanium dioxide (TiO2), using the heteroleptic (mixed-ligand) complex, bis-isopropoxy-bis-tertiarybutylacetoacetatotitanium, Ti((OPr)-Pr-i)(2)(tbaoac)(2)], as the precursor. The transformation of the as-prepared material into crystalline TiO2 was achieved by heating in air at 500 degrees C. Interestingly, the material retained its pure anatase phase even after heating at 800 degrees C. The as-prepared sample and the heated ones were characterized by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and electron microscopy (SEM, TEM) which, together, revealed that the spheres are mesoporous and, significantly, hollow. As an anode material in a Li-ion battery, the titania microspheres exhibited a high reversible capacity of 212 mA h g(-1) after 100 charge and discharge cycles and displayed excellent cycling stability.