MOF derived CeO_2/CoFe_2O_4 wrapped by pure and oxidized g-C_3N_4 sheet as effcient supercapacitor electrode and oxygen reduction reaction electrocatalyst materials

摘要

In this work, MOF-derived metal oxide/spinel metal oxide nanocomposite was successfully synthesized. Then, different amounts of pure and oxidized g-C_3N_4 were introduced to nanocomposites as modifcation treatments using preserved shape and complex appropriate features of g-C_3N_4. After mixing CeO_2/CoFe_2O_4 with pure and oxidized g-C_3N_4 sheets, the 10% Ox-g-C_3N_4/CeO_2/CoFe_2O_4 hybrid exhibited excellent supercapacitor, and 20% g-C_3N_4/CeO_2/CoFe_2O_4 shows good oxygen reduction reaction (ORR) performance. Accordingly, the 10% Ox-g-C_3N_4/CeO_2/CoFe_2O_4 electrode exhibited a high specifc capacitance (255.5 F/g). Asymmetric device (using the promising electrode as cathode and activated carbon as the anode), achieved a wide potential window up to 1.6 V with a high-power density of 11,904 W/kg and a good cycling performance with 91% capacitance retention after 3000 charge/discharge cycling test. Furthermore, the as-prepared 20% g-C_3N_4/CeO_2/CoFe_2O_4 showed good comparable to those of commercially available Pt/C electrodes in oxygen reduction reaction (ORR) performance. The enhanced capacitive and electrocatalytic properties and stability are due to the synergistic interactions between the porous pure or oxidized g-C_3N_4 sheets and CeO_2/CoFe_2O_4. The results indicate that introducing pure or oxidized g-C_3N_4 to MOF-derived metal oxide could be a useful strategy for improving the performance of energy storage devices supercapacitor and ORR catalysts.