184
S. Majidi et al.
the target surface. The plasma plume spread through the substrate and, regarding the
pressure and distance from target to surface, can be thermalized by collisions with
the background gas [112].
Glavin et al. [116] carried out the PLD method to synthesize very thin and crystalline h-BN from an amorphous BN target. The study was conducted with the
aim of the growth temperature decreasing and well-stoichiometric h-BN nanosheets
achievement. They deposited the thin h-BN films on the sapphire substances and
highly ordered pyrolytic graphite (HOPG). Then, the high area film was covered
without the separation of the micro-sized domains or any pinholes.
Alternatively, Velazquez et al. [117] fabricated mono and few-layer h-BN by
Ag films, which performed as a layer on SiTiO 3 (001) with the laser parameters
including 266 nm, 100 mJ per pulse, and 5 ns. The neutrally weak interaction of the
Ag substrates and few-layer h-BN led to the exfoliation of the as-grown h-BN layers
by a sticky tape. Although the h-BN sheets synthesized by the PLD method could
carry out the large-area production without grain boundaries or deformations, the
obtained crystallinity from this method is fairly low compared to that derived from
liquid exfoliation or CVD.
7 Research Gap
Notwithstanding the excellent developments up to date, there are also notable ambiguities to be explored in the field of using h-BN for water purification. For instance,
h-BN as a foundational substance plays an important role in the heterostructures
investigation, however, the ideal quality and size of the h-BN film are still not achieved
and the greatest single-crystal domain size is only less than 1 mm. Hence, extending
the size of h-BN domain is strongly required, especially for freestanding nanoporous
h-BN membrane fabrication; but has remained as a great challenge.
The quality and scale-up possibility of 2D h-BN membranes are also serious
requisitions for industrial applications. Furthermore, another important issue about
this type of membranes is the suffering of CVD-grown substances from inherent
deficiencies, wrinkles, and grain boundaries. Therefore, more studies are needed on
this subject [83].
The 2D membranes like GO and graphene have indicated successful performance
in the separation of various liquid and gas mixtures. In this regard, there is a quick
development of data organization available for such materials, which helps to guide
new 2D materials fabrication e.g., h-BN. In fact, most of these 2D materials have not
yet been investigated in several separation fields so that further study information is
required in this field.
S. Majidi et al.
the target surface. The plasma plume spread through the substrate and, regarding the
pressure and distance from target to surface, can be thermalized by collisions with
the background gas [112].
Glavin et al. [116] carried out the PLD method to synthesize very thin and crystalline h-BN from an amorphous BN target. The study was conducted with the
aim of the growth temperature decreasing and well-stoichiometric h-BN nanosheets
achievement. They deposited the thin h-BN films on the sapphire substances and
highly ordered pyrolytic graphite (HOPG). Then, the high area film was covered
without the separation of the micro-sized domains or any pinholes.
Alternatively, Velazquez et al. [117] fabricated mono and few-layer h-BN by
Ag films, which performed as a layer on SiTiO 3 (001) with the laser parameters
including 266 nm, 100 mJ per pulse, and 5 ns. The neutrally weak interaction of the
Ag substrates and few-layer h-BN led to the exfoliation of the as-grown h-BN layers
by a sticky tape. Although the h-BN sheets synthesized by the PLD method could
carry out the large-area production without grain boundaries or deformations, the
obtained crystallinity from this method is fairly low compared to that derived from
liquid exfoliation or CVD.
7 Research Gap
Notwithstanding the excellent developments up to date, there are also notable ambiguities to be explored in the field of using h-BN for water purification. For instance,
h-BN as a foundational substance plays an important role in the heterostructures
investigation, however, the ideal quality and size of the h-BN film are still not achieved
and the greatest single-crystal domain size is only less than 1 mm. Hence, extending
the size of h-BN domain is strongly required, especially for freestanding nanoporous
h-BN membrane fabrication; but has remained as a great challenge.
The quality and scale-up possibility of 2D h-BN membranes are also serious
requisitions for industrial applications. Furthermore, another important issue about
this type of membranes is the suffering of CVD-grown substances from inherent
deficiencies, wrinkles, and grain boundaries. Therefore, more studies are needed on
this subject [83].
The 2D membranes like GO and graphene have indicated successful performance
in the separation of various liquid and gas mixtures. In this regard, there is a quick
development of data organization available for such materials, which helps to guide
new 2D materials fabrication e.g., h-BN. In fact, most of these 2D materials have not
yet been investigated in several separation fields so that further study information is
required in this field.