Engineered porous nanopillars of Co3O4: Hydrothermal synthesis and energy storage application

Abstract

The ever increasing demand of energy for daily needs is knocking globally and in this scenario the energy storage devices were paid more attention as they store more charge and release it efficiently which can be used in many applications. Nanopillars like porous Co<inf>3</inf>O<inf>4</inf> nanostructures were synthesized by using a facile hydrothermal method which could be a potential candidate for energy storage applications. The as synthesized Co<inf>3</inf>O<inf>4</inf> nanostructures are thoroughly analyzed by diffraction and microscopic tools which corroborated its successful synthesis. The porous Co<inf>3</inf>O<inf>4</inf> nanostructures when utilized as an electrode material for supercapacitor application, a high capacitance value of 495.5 F g-1 is obtained at a scan rate of 5 mV s-1 from cyclic voltammetry (CV) data and 275 F g-1 (110 C g-1) at a current density of 1 A g-1 from charge-discharge (CD) data in 6 M KOH electrolyte. The charge bearing capacity of porous Co<inf>3</inf>O<inf>4</inf> in other electrolytes like 4 M and 2 M KOH electrolyte is also studied and a capacitance value of 361.7 and 349.5 F g-1 is obtained in 4 M, and 2 M KOH electrolyte, respectively at a scan rate of 5 mV s-1. From the experiment it is found that the charge storage capacity is decreasing as the electrolyte concentration decreases and the value is 220 F g-1 (88 C g-1), and 214 F g-1 (86 C g-1) at a current density of 1 A g-1 for 4 M and 2 M KOH, respectively. Similarly the resistance value also decreases as the electrolyte concentration is increasing and vice-versa. The exciting result produced by this novel material suggests its suitable utility for energy storage applications. © 2020 Author(s).