Metal ion-assisted conversion of Co-ZIF-L to CoNi-layered double hydroxides with high electrochemical properties for supercapacitors

Metal ion-induced etching can effectively convert zeolitic imidazolate frameworks (ZIFs) to CoNi-layered double hydroxides (LDH). Here, different metal-ion-assisted etching methods are utilized to convert Co-ZIF-L to CoNi-LDH with various morphologies and electrochemical properties . The resultant CoNi-LDH (CoNi-1) with a composition of Co 0.7 Ni 0.3 (OH) 2 displayed a high electrochemical performance when Co-ZIF-L was treated in N, N -dimethylformamide-ethanol solution containing Co 2+ ions followed by Ni 2+ ion-induced etching under hydrothermal condition. The improved electrochemical performance of CoNi-1 can be attributed to structural advantages, where the well-dispersed ultrathin CoNi-LDH layers favor the exposure of surface active sites and promote ion diffusion to maximize electrochemical properties.