Bio-engineered hexagon-shaped Co3O4 nanoplates on deoxyribonucleic acid (DNA) scaffold: An efficient electrode material for an asymmetric supercapacitor and electrocatalysis application

Using biological scaffolds to template inorganic materials provides a method for creating accurate composite nanostructures of various dimensions. Herein, we demonstrate the preparation of hexagon-shaped spinel structured Co3O4 nanoplates using a deoxyribonucleic acid (DNA) mediated co-precipitation method. The DNA template effectively tuned the morphological properties of the Co3O4 materials and provided the hexagonal shaped nanostructures. The Co3O4 hexagons show a battery-type energy storage mechanism and provide 739 C g−1 of specific capacity at 1 A g−1 in 6 M KOH electrolyte. The asymmetric supercapacitor device such as Co3O4//activated carbon (AC) delivered 186 C g−1 of specific capacity at 1 A g−1 and exhibited the energy and power densities of 66.1 Wh kg−1 and 1652 W kg−1, respectively. In studies of the oxygen evolution reaction with a three-electrode cell in 0.1 M H2SO4, the Co3O4 electrocatalyst showed a small overpotential of 460 mV at 0.5 mA cm−2 and Tafel slope of 58.93 mV/dec with excellent stability at room temperature. This study provides a route for preparing other metal oxide nanostructures by utilizing a bio-template in a short time scale with high yields at room temperature.