3.2. Raman analysis
Raman spectroscopy is an effective technique for confirmation
for born doping in graphene sheets. The Raman spectra of T-GNS and HB-GNS are illustrated in Fig. 3. Shows the T-GNS an intense Gband
at 1585 cm1 and disorder band (D-band) at 1350 cm1 and
also a broad 2D band appear at 2795 cm1
. The D band disorders
mode in T-GNS represents the presence of small functional groups
in graphene sheets. But, the intensity of the D band is small due to
thermal reduction [34]. HB-GNS shows the graphitic SP2 hybridized
Raman peak at 1567 cm1 (G-band) and also shows a strong
high intensity disorder D-band at 1345 cm1 due to boron doping
in graphene structure and their second disorder phonon mode
(2D-band) appear at 2689 cm1
. In addition to 2D band, graphitic
and disorder (G + D) peaks appears at 2913 cm1 in HB-GNS. The 2D
band in HB-GNS indicates that the graphene sheet may contain few
layers [35,36]. The T-GNS and HB-GNS intensity ratio (ID/IG) is 0.92
and 1.19 with higher intensity in HB-GNS due to boron doping in
graphene nanosheets [37].
3.3.