Reverse microemulsion synthesis of CeO2 nanopowder using polyoxyethylene(23)lauryl ether as a surfactant

Ceria nanoparticles were synthesized via reverse microemulsion method using polyoxyethylene(23)lauryl ether as a surfactant. The obtained powders were characterized by X-ray diffraction (XRD) and their mean grain size and morphology were determined by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Chemical bonds, thermal history and surface area of the synthesized powders were investigated using Fourier transform infrared spectroscopy (FTIR), differential thermal analysis (DTA) and Brunauer–Emmett–Teller surface area measurement (BET), respectively. The optical reflectance was determined by UV–visible diffuse reflectance spectra (DRS). The formation of cubic ceria was confirmed by XRD. The average particles size was about 15 nm for microemulsion samples and 27 nm for direct precipitation samples. The BET surface area increased to around 64 m2/g, with increasing calcination at 300 °C; then, it decreased following calcination at higher temperatures. The band gap energy of CeO2 decreased from 3.77 eV to 3.61 eV as the calcination temperature increased from 80 °C to 700 °C.