Nicolet 360 spectrometer

Fourier transform-infrared (FTIR) spectra were collected on a Thermo Nicolet-360 spectrometer (USA). The elemental content of carbon, hydrogen, and chlorine were analyzed with a Vario Macro EL analyzer (Germany). Thermogravimetric analysis (TGA) was performed to determine the pyrolysis samples by using an HCT-1 instrument (China). Samples morphologies were observed by JSM-6700F scanning electron microscope (FESEM, Japan) and by using a Tecnai-G20 transmission electron microscopy (TEM, USA). Surface chemical composition of samples was studied by X-ray photoelectron spectroscopy (XPS, Thermo ESCALAB250, USA). The surface area and porosity of the samples were estimated from the isotherms of nitrogen adsorption–desorption at 77 K by ASAP2020. The specific surface area was calculated with the Brunauer–Emmett–Teller (BET) equation. The pore size distribution of the samples was calculated based on the density functional theory (DFT) method.

Fourier transform infrared spectroscopy (FTIR) was performed on a Thermo Nicolet-360 spectrometer (USA). Elemental analysis (EA) (carbon, hydrogen, oxygen and nitrogen) was done with a Vario Macro EL analyzer (Germany). Thermogravimetric analysis (TGA) was performed using a HCT-1 instrument (China). Surface morphology of HPCs were analyzed by a JSM-6700F field emission scanning-electron microscope (FESEM, Japan). Powder X-ray diffraction (XRD) spectra and Raman spectra were recorded on a D8 ADVANCE A25 X-ray powder diffractometer (Germany) using Cu-Kα radiation (λ = 1.541 Å) and a 769G05 laser Raman spectrometer (UK), respectively. Surface chemical composition was determined by X-ray photoelectron spectroscopy (XPS) on a Thermo ESCALAB250, USA. The surface area and porosity of HPCs were estimated from the isotherms of nitrogen adsorption–desorption at 77 K by Accelerated Surface Area & Porosimetry (ASAP2020). The specific surface area was calculated by Brunauer–Emmett–Teller (BET) equation. The pore-size (diameter) distributions (PSDs) were determined using the nonlocal-density functional theory, assuming slit-pores geometry.