The infrared spectra (4000–400 cm−1) using KBr pellets of
the solid samples were performed on a Fourier trans-form infrared
spectrometer (FT-IR) (FT-IR Spectrum One Spectrometer, Perkin
Elmer Co., USA). Brunauer Emmett Teller’s (BET) test degassing
model was Heating-Vacuum at 50 ◦C for 60 min with nitrogen as the
adsorbents, while the saturated vapor pressure was 1.0180 bar and
ambient temperature was 25 ◦C. ESI–MS was performed on APEX
IV Fourier transform ion cyclotron resonance mass spectromete