Integrated hybrid of graphitic carbon-encapsulated CuxO on multilayered mesoporous carbon from copper MOFs and polyaniline for asymmetric supercapacitor and oxygen reduction reactions

Abstract Hybrid electrode materials composed of metal-organic framework (MOF)-derived oxides and conducting polymers have abundant potential for energy applications. The energy storage and conversion phenomena of such materials are due to their high porosity, long stability, good conductivity, low charge transport resistance, and fast charge-discharge rate. Herein, CuxO-C/PANI is synthesized by the in situ polymerization of aniline on multilayered mesoporous CuxO-C from Cu-MOF. Such an integrated hybrid can provide a potential route for electron transfer and improve the kinetics of redox reactions. Subsequently, the CuxO-C/PANI composite demonstrates a maximum specific capacitance of 1308 F g-1 at 1 A g-1 in a 3-electrode system. Additionally, as a fabricated device, CuxO-C/PANI//ZIF-8NPC shows an uppermost energy density of 55.1 W h kg-1 (at a 862.4 W kg-1 power density) and power density of 8668.2 W kg-1 (at a 30.1 W h kg-1 energy density), with 88.3% capacitance retention, even after 10000 cycles. Additionally, CuxO-C/PANI, as an efficient oxygen reduction catalyst, delivers an outstanding onset potential (0.94 V) and half-wave potential (0.76 V) against the reversible hydrogen electrode with good stability. Hence, these results show that the as-fabricated electrode material is an efficient alternative electrocatalyst for energy storage and oxygen reduction applications.