Vapor solid phase grown hierarchical CuxO NWs integrated MOFs-derived CoS2 electrode for high-performance asymmetric supercapacitors and the oxygen evolution reaction

Abstract

Designing and exploring a simple, novel, and smart synthetic concept to fabricate highly efficient and dual-function electrode material at an optimum cost for green energy harvesters has been a long-standing challenge. Herein, for the first time, we investigated a simple and smart concept to fabricate dual-function vapor solid phase grown copper oxide nanowires (CuxO NWs) integrated metal-organic frameworks-derived (MOFs) hollow and porous cobalt sulfide (CuxO NWs@CoS2) hybrid nanostructures as an effective binder-free electrode for supercapacitors and the OER. When utilized as an electrode material for supercapacitors, the CuxO NWs@CoS2 hybrid electrode displayed an ultrahigh specific capacity of 331.6 mAh/g (volumetric capacity of 2.46 mAh/cm3) with an outstanding rate capability of 67% even at a high current density of 50 mA/cm2; moreover, the electrode possessed a long-term durability of 100.2% after 10,000 cycles. An all-solid-state asymmetric device (CuxO NWs NWs@CoS2//Fe2O3/rGO aerogels) delivered a specific energy density of 49.8 Wh/kg. In addition, the oxygen evolution activity of the CuxO NWs@CoS2 electrode was also investigated and the electrode demonstrated superior catalytic properties compared to other formulations. This investigation emphasizes a novel synthetic approach and its multifunctional applicability in energy storage and generation devices.