4. Characterization of GO membranes
The morphology and thickness of the GO membranes were
characterized by field emission scanning electron microscopy
(FESEM). FESEM were taken on an S-4800 (Hitachi) with a cold
field emission gun operated at 4 kV and 10 mA. The surface chemical
compositions of the GO membranes were analyzed by X-ray
photoelectron spectroscopy (XPS, Axis Ultra DLD, Kratos) with a Al
Kα line as an X-ray source and. The phase purity and crystallinity
of the GO membrane was confirmed by X-ray diffraction (XRD).
The XRD patterns were recorded at ambient conditions with
Bruker D8 ADVANCE X-ray diffractometer with Cu Kα radiation at
40 kV and 40 mA. The functional groups of GO membrane were
measured by an FT-IR spectrum (Nicolet 6700, Thermo Scientific,
USA). The chemical compositions of the GO membranes after
seawater desalination were analyzed by energy-dispersive X-ray
spectroscopy (EDXS) using the same FESEM microscope at 20 kV.