In this study, a
facile, novel, ecofriendly method has been demonstrated
for the fabrication of hexagonal boron nitride nanosheets (h-BNNs)
by ultrasound-assisted exfoliation of h-boron nitride (h-BN) using
various extracts of plant materials. Plant extract can be used for
nanoparticle synthesis by acting as a reducing, capping, and stabilizing
agent. Similarly, plant extract can function as a green surfactant
by adsorbing on the surface of h-BN and, by weakening the interlayer
interaction, slowly exfoliating h-BN in the form of layer h-BNNs.
The product of exfoliation was confirmed by characterization with
UV–visible spectrophotometry, Fourier transform infrared spectroscopy,
X-ray diffraction, Raman spectroscopy, transmission electron microscopy,
scanning electron microscopy, energy-dispersive X-ray spectroscopy,
atomic force microscopy, and X-ray photoelectron spectroscopy. Phytoexfoliated
h-BNNs were applied for the removal of both cationic and anionic dyes
from water, as an antioxidant, and to improve mechanical properties
of biobased polyurethane composites. Stable dispersibility of h-BNNs
in water was confirmed via stability experiments. Compared to that
of the pristine h-BN and the control (h-BNNs synthesized using isopropanol),
the plant-material-synthesized h-BNNs showed higher removal efficiency
for both cationic and anionic dyes. Improved radical scavenging activities
and mechanical properties in castor oil-based polyurethane composites
were also shown. This novel and facile approach provides a convenient
strategy for stable and scalable exfoliation of h-BN, which might
find wide applications in different fields.