Microstructure construction and composition modification of CeO2 macrospheres with superior performance

Abstract

Macro/nano-composite CeO₂ spheres with variable diameters of 30–300 μm assembled from nanoparticles of 5–8 nm were synthesized through the calcination of the well assembled spherical Ce(COOH)₃ precursor. The controlled hydrolysis of DMF is the key factor for both the crystallization of Ce(COOH)₃ and the formation of its macrospheres. These hierarchical CeO₂ macrospheres possess pretty high specific surface areas of up to ∼190 m² g⁻¹ and show an excellent ability to remove Cr(VI) from aqueous solution. Moreover, when substituted with Bi(III), the oxygen storage capacity (OSC) of these CeO₂ spheres could be improved sharply to 3243.75 μmol [O] g⁻¹. With an easy-to-manipulate macroscale spherical morphology, these materials are easily recycled. This synthesis opens a promising route for high performance metal oxides.