Biomass-derived porous carbon materials with NiS nanoparticles for high performance supercapacitors

3D nanoparticles were synthesized by facile hydrothermal method with the hexamethylenetetramine as soft templates. The effects of reaction temperature and time on electrochemical properties were seriously studied in this research. The optimal specific capacitance 1688.5 F g⁻¹ at the current density of 1 A g⁻¹ was obtained when the temperature is 180 °C and reaction time is 8 h. Through combining the nanoparticles with the natural biomass carbon materials, the 3D open-pore silk ribbon like architecture is acquired when the carbonization temperature of the walnut shell is 600 °C. Electrochemical studies manifest that the NiS/C-600 composites have better electrical conductivity and electrochemical rate performance. The final satisfactory electrochemical behaviors deprived from the introduction of walnut shells opens a novel route of biomass carbon electrode materials for excellent performance energy device.