Facile synthesis of 3D porous Co3V2O8 nanoroses and 2D NiCo2V2O8 nanoplates for high performance supercapacitors and their electrocatalytic oxygen evolution reaction properties.

Binary metal oxides have recently attracted extensive attention from researchers in the energy storage and conversion field due to their high energy densities and multiple oxidation states. Novel 3D Co3V2O8 porous rose-like structures and 2D NiCo2V2O8 nanoplates were facilely synthesized via a solvothermal method, and the morphologies, Ni/Co ratios, and surface area of these samples can be easily tuned in the same procedure. The as-prepared Co3V2O8 porous rose-like structure exhibited good electrocatalytic oxygen evolution performance with excellent activity and stability. In addition, 2D NiCo2V2O8 nanoplates delivered a high specific capacitance of 1098.9 F g-1 at 4 A g-1 and good cycling stability (remaining 68% after 7000 cycles) in aqueous KOH electrolyte. The NiCo2V2O8 nanoplates inherit the pseudocapacitive benefits of both Ni3V2O8 and Co3V2O8, showing a higher specific capacitance than pure Co3V2O8 porous rose-like structures.