The surface morphologies of the AC samples were characterized using scanning electron microscopy (SEM; EM-30 Plus, COXEM, Daejeon, Korea). For better observation, the samples were sprayed with gold before testing to increase their surface conductivities.
The AC surface functional groups were identified via Fourier transform infrared spectroscopy (FTIR, Thermo Nicolet iS5, Thermo Fisher Scientific, Waltham, MA, USA). The samples were characterized in the infrared region using the potassium bromide sheet method at 25 °C with wavenumbers ranging from 4000 to 600 cm−1, 32 scans and 4 cm−1 resolution. The sample profiles were retrieved and analyzed using an infrared atlas database.
The nitrogen adsorption–desorption isotherms and other pore properties were determined at a pretreatment temperature of 200 °C and time of 6 h using a surface-area pore analyzer (ASAP 2460, Mac, Atlanta, GA, USA). The Brunauer–Emmett–Teller (BET) method was used to calculate the specific surface area.
The AC surface functional groups were identified via Fourier transform infrared spectroscopy (FTIR, Thermo Nicolet iS5, Thermo Fisher Scientific, Waltham, MA, USA). The samples were characterized in the infrared region using the potassium bromide sheet method at 25 °C with wavenumbers ranging from 4000 to 600 cm−1, 32 scans and 4 cm−1 resolution. The sample profiles were retrieved and analyzed using an infrared atlas database.
The nitrogen adsorption–desorption isotherms and other pore properties were determined at a pretreatment temperature of 200 °C and time of 6 h using a surface-area pore analyzer (ASAP 2460, Mac, Atlanta, GA, USA). The Brunauer–Emmett–Teller (BET) method was used to calculate the specific surface area.