Microwave-assisted hydrothermal synthesis and characterisation of cobalt phosphate nanosheets as electrode material for high-performance supercapacitors

In this study, cobalt phosphate (Co₃[PO₄]₂) nanosheets were synthesized through a microwave-assisted hydrothermal method with enhanced electrochemical properties. The synthesis was carried out at different microwave heating times (3, 5, 10, and 15 min) at a fixed temperature of 200°C. The structural properties of the synthesized Co₃(PO₄)₂ nanosheets were investigated via XRD, FESEM-EDS and TEM studies, while the electrochemical parameters were evaluated through CV, GCD, and EIS in a standard 3-electrode cell with 1 M KOH as an electrolyte at a room temperature. The results reveal that Co₃(PO₄)₂ nanosheets synthesized at 5 min microwave heating time exhibited maximum electrochemical performance owing to its excellent structural and morphological properties and thus reported a specific capacity of 130.98 and 164.52 C/g at a scan rate of 10 mV/s and a current density of 1 A/g, respectively. Furthermore, a stability test of the synthesized electrode material reported excellent cyclic stability of the electrode with 101% retention of the initial value of its specific capacity after 1000 cycles.