Unique redox properties in defective CeO2-x nanocrystallines synthesized by laser melting

Abstract

Defects in cerium oxide, especially oxygen vacancies, play an essential role in its versatile applications and are efficiently preserved at ambient conditions in a nonequilibrium process. Herein, defective CeO2-x with heterogeneous structure was synthesized by high-energy laser melting, where a large amount of oxygen vacancies and Ce3+ could be introduced, leading to improved visible light absorption, narrowed bandgap and room temperature ferromagnetism. Moreover, this laser melted CeO2-x exhibits significantly enhanced low-temperature oxidation behaviors than the counterpart prepared by normal hydrogen-reduction. This unique redox performance could be attributed to the intragranular diffusion at the boundaries of assembled nanocrystallites. This method paves a new way for introducing unique multi-functions in oxide ceramics.