Synthesis and characterization of aerogel-like mesoporous nickel oxide for electrochemical suporcapacitors

Highly porous NiO was prepared via a combination of sol-gel process with supercritical drying method in this paper. The as-synthesized NiO samples exhibit 80-90% porosity and high surface area, ie, 180.5-325.6 m(2) g(-1) Cyclic voltammetric and chronopotentiometric measurements indicated the acrogel-like NiO in 1 mol.L-1 KOH solution to behave capacitive well due to its uniform mesoporous microstructure. It was also observed that post-heating temperature plays a critical role in the mesoporous nature of the aerogel-like materials. An optimal heating temperature of 300 degrees C was found to favor the formation of mesopores, which account for the large specific capacitance of as high as 125 Fg(-1). The average specific capacitance of the aerogellike NiO was observed to be about 75-125 F.g(-1) between a potential window of 0-0.35 V vs. SCE.