Enhanced electrochemical capacitance of nanoporous NiO based on an eggshell membrane

Porous NiO nanospheres are synthesised with the assistance of an eggshell membrane. The resulting NiO nanospheres are composed of well distributed nanoparticles of 5-10 nm in diameter with high surface areas and good electrolyte wetting, which result in a good capacitive performance of 550 F g(-1) at a current density of 1 A g(-1) in 2 M KOH aqueous solution.