NiO nanosheets anchored on honeycomb porous carbon derived from wheat husk for symmetric supercapacitor with high performance

NiO nanosheets were anchored at honeycomb amorphous porous carbon with ultrahigh surface area derived from activated wheat husk to obtain NiO@PC (porous carbon). The ultrahigh surface area of PC (634.4 m² g⁻¹) promoted the attachment of NiO nanosheets, and this hierarchical nanostructure (NiO@PC) was beneficial for facilitating electron and electrolyte ion transport and accelerating the reversible redox reaction, which successfully demonstrated its high energy storage properties as supercapacitor. The NiO@PC composite exhibited brilliant capacitance of 500 F g⁻¹ at 10 A g⁻¹ after 8000 cycles. Moreover, as symmetric supercapacitor, NiO@PC exhibited high specific capacitance of 76 mF cm⁻² at 1 mA cm⁻². The excellent electrochemistry performance of NiO@PC brings the possibility of using biomass waste as electrode materials for energy storage. This process is facile and environmental friendly.