Biotemplate-assisted hydrothermal synthesis of tubular porous Co3O4 with excellent charge-discharge cycle stability for supercapacitive electrodes

Tubular porous Co3O4 were hydrothermally synthesized at 120 °C and post-calcined at 500 °C using sorghum straw as biotemplate. The as-obtained porous Co3O4 inherited the morphology and microstructure of sorghum straw. Compared with the bare Co3O4, the tubular porous Co3O4 exhibited 5-fold enhancement in specific capacitance and excellent charge-discharge cycle stability with the capacitance retention of 90.1% after 9000 cycles at a current density of 2 A/g, attributed to its enhanced specific surface area, more surface electroactive sites and unique microstructure.