3.2. FT-IR spectroscopy
Fourier transform infrared (FTIR) spectroscopy was carried out using a Nicolet Magna-IR 830 spectrometer using the attenuated total reflectance (ATR) method. The spectrum was generated and collected 64 times and corrected for the background noise.
3.3. XRD
X-ray diffraction (XRD) measurements were conducted using powder diffraction procedures. Adsorbents were grounded to powder size and then analyzed by a CuKα radiation generated in a Phillips X’Pert X-ray diffractometer.
3.4. Thermal analysis
Thermogravimetric (TG) curves were obtained using a TA Instruments Thermal Analyzer (New Castle, DE, USA). The heating rate was 10 °C min−1 in a helium atmosphere at 100 mL min−1 flow rate. The samples were heated up to 1000 °C. From the TG curves, differential TG (DTG) curves were derived.