Controllable synthesis of CoMoO4-modified NiMoO4: a stepwise chemical etching method of materials for hybrid supercapacitors

Multi-component electrode materials with novel structures are highly pursued to the assembly of high-performance hybrid supercapacitors. In this paper, we have prepared CoMoO₄-modified NiMoO₄ and nitrogen-doped porous carbon by using α-MoO₃ and ZIF-8/ZIF-67 as sacrificial templates. In particular, α-MoO₃ and ZIF-67 were also used as the molybdenum and cobalt sources for the in situ synthesis of NiMoO₄ and CoMoO₄, respectively. The structural construction and surface modification of the NiMoO₄ electrode were realized under mild reaction conditions. As compared with the pristine NiMoO₄, the electrochemical properties of CoMoO₄-modified NiMoO₄ were significantly improved. The maximal capacity of the CoMoO₄-modified NiMoO₄ under 3-electrode system is 522.5 C g⁻¹. When the power density is 800 W kg⁻¹, the maximum energy density of the hybrid supercapacitor based on CoMoO₄-modified NiMoO₄ and nitrogen-doped porous carbon is 41.29 Wh kg⁻¹. All electrochemical results indicate that multi-component electrodes prepared by our sacrificial template strategy have the possibility to be applied in hybrid energy storage equipment.