2.2. Physical and chemical measurements
X-ray diffraction (XRD) analysis was carried out on Phillips
X’Pert diffractometer with Cu Ka radiation. Scanning electron microscopy (SEM) was performed on JEOL 6700F Field Emission
Scanning Electron Microscope equipped with INCA x-sight energy
dispersive X-ray spectroscopy. The samples were coated with carbon
before the SEM analysis. The pH in solution was measured
using a pH meter with glass electrode. The specific surface area
of the samples was determined by the NOVA 1000e using BET
nitrogen gas sorption method.
Sorption of phosphate was measured spectrophotometrically
using the molybdenum-blue ascorbic acid method