Morphological and surface chemical composition disorder induced efficient oxygen evolution and supercapacitor processes into Co3O4 nanostructures

In this study, a high-efficiency electrode material based on Co3O4 was designed. The electrochemical properties were enhanced when orange peel extract was added during the synthesis of Co3O4 using modified hydrothermal process. When electrolyzed with 1 M KOH, 10 mL of orange peel extract mediated Co3O4 (sample 2) exhibited 310 mV overpotential at 20 mA/cm2 and a Tafel slope of 75 mVdec-1. Tests conducted on sample 2 based on Co3O4 over a period of 30 h indicated that it was highly durable at different current densities. Among three electrode cells set up in 3 M KOH electrolytic solution, sample 2 of Co3O4 displayed a higher specific capacitance of 2021.88 F/g and a higher energy density of 44.93 Wh/Kg at 1.25 A/g. Using sample 2 of Co3O4 as an anode material, the ASC device demonstrated a specific capacitance of 1144.0 F/g and an energy density of 24.95 Wh/ Kg at 1.25 A/g. Additionally, the specific capacitance retention percentage during 30,000 GCD cycles at 1.25 A/g and the columbic efficiency were estimated to be about 98.6 %. The improved electrochemical activity of sample 2 of Co3O4 may be attributed to reduced optical band gaps, altered particle shapes, reduced particle sizes, and abundant oxygen vacancies. Because of its eco-friendly and low-cost characteristics, orange peel extract could be an excellent alternative option for the design of next generation electrode materials for high performance.