Effect of surfactants and digestion time on nanocrystalline cerium oxide characteristics synthesized by differential precipitation

چکیده مقاله

Nanocrystalline ceria has been synthesized by differential precipitation method in presence of poly-vinyl-pyrolidone (PVP) and polyethylene glycol (PEG) as surfactants. Sodium carbonate (Na2CO3) was used as an precipitation agent. The precipitate was digested for 4–12 h, dried at 80 °C for 24 h and, then calcinated at 400 °C for 4 h. The nanocrystalline ceria was characterized by thermo gravimetric analysis (TGA), X-ray diffraction (XRD), N2 adsorption/desorption (BET) and scanning electron microscopy (SEM). The digestion time, type and amount of surfactant materials were optimized to provide nanocrystalline ceria with high surface area. The results revealed that the surfactant agent increases the surface area due to decrease of crystalline size. Furthermore, PEG surfactant resulted in formation of smaller particles compared to PVP. Moreover, increasing the digestion time to 8 h, improves the samples pore volume and surface area. The nanocrystalline ceria was synthesized with surface area of 102.8 m2/g and crystalline size of 8 nm in presence of surfactant.