Composition engineering of ZIF-derived cobalt phosphide/cobalt monoxide heterostructures for high-performance asymmetric supercapacitors

The fabrication of interpenetrated heterostructures from desirable energy materials for the development efficient supercapacitors is promising yet challenging. Herein, a leaf-shaped cobalt phosphide/cobalt oxide heterostructure, (CoPx)1-y/CoOy (0.44 > y 0.06), was synthesized 2D-zeolitic-imidazolate-framework (ZIF-Co-L) molecular precursor via phosphidation Co3O4 intermediate. construction heterostructure through variation surface/bulk composition significantly alters interfacial properties and electronic structure, yielding enhanced supercapacitor performance. Further, gas-phase entails core–shell formation mechanism gas diffusion, regulated by Kirkendall effect. optimized (y = 0.10) exhibits remarkable derived CoO/Co0/CoP interface, thus facilitating high specific capacitance (467 F g?1 at 5 A g?1) excellent cycling stability (~91% after 10000 cycles) 30 g?1. further increase in cyclability (~107%) achieved employing graphene hybrid. an asymmetric device fabricated, that delivers reasonably density 12.7 Wh kg?1 power 370 W ~93% cycles. This study reports on modulation CoPx/CoO to enhance storage performance bulk/surface compositional variation, thereby providing strategy develop electrodes high-performance supercapacitor.