A surface control strategy of CeO2 nanocrystals for enhancing adsorption removal of Congo red

CeO2 nanocrystals with different surface structures are synthesized for studying an improvement strategy to the enhanced adsorption removal performance of Congo red. CeO2 nanonetworks possess a cerium-rich surface with more Ce4+. However, CeO2 nanorods have an oxygen-rich surface with more low-temperature reducible oxygen promoted by more defective structures, and the oxygen-rich surface of CeO2 nanoparticles is occupied by more surface-adsorbed oxygen. The effect of CeO2 surface structure is investigated by evaluating the adsorption removal capacity of Congo red. The cerium-rich surface of CeO2 nanonetworks exhibits the distinctly increased adsorption removal performance relative to the oxygen-rich surface of CeO2 nanocrystals. CeO2 nanorods with more easily reducible oxygen surface show higher adsorption removal performance than CeO2 nanoparticles with more surface-adsorbed oxygen due to more favorable textural properties and easy reducibility of more surface oxygen.