Facile synthetic route to hollow gadolinium oxide spheres with tunable thickness

Uniform rare-earth gadolinium oxide (Gd2O3) hollow spheres with tunable shell thickness have been successfully fabricated in the presence of SiO2 as templates via a urea-based homogeneous precipitation method. The synthesis is a mild, low-cost and convenient method without any catalysts. By varying the times of the precipitation procedure, the shell thickness can be successfully controlled within the 20–55 nm range. The thickness increase of each coating might be ∼10 nm. The as-synthesised product was identified from X-ray diffraction pattern, scanning electron microscopy and energy dispersive X-ray. The prepared hollow Gd2O3 spheres with tunable shell thickness and fluorescence property have the potential to be used for drug delivery, fluorescent labelling and controlled release applications.