Improving the sinterability of CeO₂ by using plane-selective nanocubes

CeO₂ nanocubes with (100) surface orientation are successfully synthesized and found to facilitate the sinterability of CeO₂ material. The CeO₂ nanocubes show a much-improved sinterability relative to CeO₂ nanoparticles prepared by the conventional citric-nitrate method. The nanocubes can be successfully sintered at a relatively low temperature of 1200 °C without using any sintering aids. In contrast, a pellet using conventional CeO₂ nano-powder obtained from the conventional citric-nitrate method can be densified only after sintering at 1400 °C, which is 200 °C higher than that for the CeO₂ nanocube sintering, although the starting particle size of both CeO₂ samples is similar. Density functional theory indicates that the surface energy of the (100) plane is significantly higher than that of the (111) plane, which is the more typical surface presentation of conventional CeO₂ particles. This high surface energy allows fast growth of the CeO₂ nanocubes during sintering, contributing to their improved sinterability.