Preparation of high-value porous carbon by microwave treatment of chili straw pyrolysis residue

Microwave technology is utilized to prepare porous carbon from the chili straw pyrolysis residue in this study. As the pyrolysis temperature increases, the thermal stability of biochar is higher. The carbon speciation of the porous carbon PC500 is closest to that of graphite, and its inorganic-C reaches to 51.21%. Notably, the specific surface area of the activated porous carbon increases with increasing pyrolysis temperature, with a maximum value of 2768.52 m2/g for PC500. Further testing of the electrochemical properties of the porous carbon, PC500 possesses a high specific capacitance of 352F/g at 1 A/g while that of conventional heating is only 226.1F/g. The porous carbon prepared by microwave heating has better electrical properties compared to conventional heating, and the biochar obtained at higher pyrolysis temperature has a richer pore structure after activation.