A facile ion-conversion-exchange strategy for designing nitrogen-doped CoMoO4@Co3O4 double-shell nanoboxs: A competitive candidate for supercapacitor and oxygen evolution reaction

摘要

Co3O4 has been paid much attention in the field of supercapacitors and oxygen evolution reaction attributed to its high theoretically specific capacitance, earth abundant, cost-effective, and environment friendly. However, the commercial application of Co3O4 was greatly limited by the poor electrical conductivity and inferior active sites. Herein, the N-CoMoO4@Co3O4 double-shell nanoboxs were successfully prepared through in situ ion-conversion-exchange treatment coupled with the following calcination process. The hollow/porous transition metal oxide-based nanomaterials delivered large surface areas and rich active sites, and boosted electron transfer. Hybridizing with other components increased electrochemical reactive active sites, optimized the superiority of different components. The nitrogen doping resulted in high density of surface reaction sites. As a result, the obtained N-CoMoO4@Co3O4 double-shell nanoboxs performed superior specific capacitance (520 F/g), favorable charge/discharge rate and remarkable cycling stability. Moreover, the advanced asymmetrical supercapacitors prepared by N-CoMoO4@Co3O4 double-shell nanoboxs supplied remarkable energy density. Furthermore, when employed as oxygen evolution reaction electrocatalysts, N-CoMoO4@Co3O4 double-shell nanoboxs yielded favorable desirable overpotential (380 mA/cm(2)) and low Tafel slope of 87.8 mV/dec. Overall, this work provided theoretical guidance for the design of efficient dual-function electrocatalysts.