2.5 Nanosheets and Water Splitting Reactions
21
reactions and hence highly improve electrocatalytic performance. For the preparation of these nanosheets Ni (OH) 2 nanoparticles were prepared first over the surface
of rGO by hydrothermal process. Later on, the Ni/rGO composite was made by the
reduction of Ni(OH) 2 /rGO at 500 °C in Ar/H 2 atmosphere. These nanosheets were
characterized by infrared (IR) imaging, TEM, XRD, Raman spectroscopy, and X-ray
photoelectron spectroscopy (XPS) [25].
In a relatively new research, cauliflower-like nanosheets have been developed with
superior photocatalytic activity for generation of hydrogen with water splitting reaction. Ternary ZnS/CuS/g-C 3 N 4 cauliflower-like composite nanosheets were fabricated via hydrothermal, cation exchange process along with ultrasound supported
wet impregnation techniques. These nanosheets have proven to be very efficient
for generation of hydrogen. Maximum hydrogen liberation rate of 9868 μ mol h
−1
g
−1 was obtained. The hydrogen liberated by ternary ZnS/CuS/g-C 3 N 4 is almost
double than the amount generated by simple CuS/ZnS. This is maximum amount
of hydrogen generated by g-C 3 N 4 -based nanocomposites. This remarkable performance is attributed to the exclusive heterostructure of ternary CuS/ZnS/g-C 3 N 4
which have possibly restrained the rejoining of electron/hole pairs. The nanosheets
also showed remarkable recycling performance. For the preparation of ternary
ZnS/CuS/g-C 3 N 4 , ZnS, CuS/ZnS nanocomposites, and g-C 3 N 4 were prepared separately by hydrothermal method, cation exchange method, and heating the melamine,
respectively. Afterward, the nanosheets were fabricated by ultrasonic-aided wet
impregnation technique. The prepared nanostructures were characterized by FTIR,
XRD, XPS, SEM, TEM, etc. [26].
Snowflake-like multi-channel Ru/Cu nanosheets are also reported for their efficiency as electrocatalysts for HER and OER via water splitting reactions. These
metallic nanosheets were composed of amorphous Cu and crystalline Ru which
depicted efficient liberation of hydrogen and oxygen from water splitting in both
alkaline and acidic conditions at lower onset and overpotential as compared to the
commercially available Ir
C
Pt
C Ir/C||Pt/C electrocatalyst. These nanosheets have
also shown excellent stability in both alkaline and acidic environments as indicated
by the chronoamperometry measurements. These nanosheets were prepared by the
one-pot process with RuCl 3 · xH2O and CuCl 2 · 2H 2 O. Oleylamine and octadecene
were employed as solvents and phloroglucinol as the reducing agent. The prepared
nanosheets were characterized by TEM, AFM, EDX, dark-field scanning TEM, etc.
[27].
2.6 Other Nanomaterials and Water Splitting Reaction
Other than abovementioned nanomaterials there are several other nanoscale
substances that are involved in the water splitting reaction for the generation of
hydrogen. Some of them are listed in Table 1.1.
21
reactions and hence highly improve electrocatalytic performance. For the preparation of these nanosheets Ni (OH) 2 nanoparticles were prepared first over the surface
of rGO by hydrothermal process. Later on, the Ni/rGO composite was made by the
reduction of Ni(OH) 2 /rGO at 500 °C in Ar/H 2 atmosphere. These nanosheets were
characterized by infrared (IR) imaging, TEM, XRD, Raman spectroscopy, and X-ray
photoelectron spectroscopy (XPS) [25].
In a relatively new research, cauliflower-like nanosheets have been developed with
superior photocatalytic activity for generation of hydrogen with water splitting reaction. Ternary ZnS/CuS/g-C 3 N 4 cauliflower-like composite nanosheets were fabricated via hydrothermal, cation exchange process along with ultrasound supported
wet impregnation techniques. These nanosheets have proven to be very efficient
for generation of hydrogen. Maximum hydrogen liberation rate of 9868 μ mol h
−1
g
−1 was obtained. The hydrogen liberated by ternary ZnS/CuS/g-C 3 N 4 is almost
double than the amount generated by simple CuS/ZnS. This is maximum amount
of hydrogen generated by g-C 3 N 4 -based nanocomposites. This remarkable performance is attributed to the exclusive heterostructure of ternary CuS/ZnS/g-C 3 N 4
which have possibly restrained the rejoining of electron/hole pairs. The nanosheets
also showed remarkable recycling performance. For the preparation of ternary
ZnS/CuS/g-C 3 N 4 , ZnS, CuS/ZnS nanocomposites, and g-C 3 N 4 were prepared separately by hydrothermal method, cation exchange method, and heating the melamine,
respectively. Afterward, the nanosheets were fabricated by ultrasonic-aided wet
impregnation technique. The prepared nanostructures were characterized by FTIR,
XRD, XPS, SEM, TEM, etc. [26].
Snowflake-like multi-channel Ru/Cu nanosheets are also reported for their efficiency as electrocatalysts for HER and OER via water splitting reactions. These
metallic nanosheets were composed of amorphous Cu and crystalline Ru which
depicted efficient liberation of hydrogen and oxygen from water splitting in both
alkaline and acidic conditions at lower onset and overpotential as compared to the
commercially available Ir
C
Pt
C Ir/C||Pt/C electrocatalyst. These nanosheets have
also shown excellent stability in both alkaline and acidic environments as indicated
by the chronoamperometry measurements. These nanosheets were prepared by the
one-pot process with RuCl 3 · xH2O and CuCl 2 · 2H 2 O. Oleylamine and octadecene
were employed as solvents and phloroglucinol as the reducing agent. The prepared
nanosheets were characterized by TEM, AFM, EDX, dark-field scanning TEM, etc.
[27].
2.6 Other Nanomaterials and Water Splitting Reaction
Other than abovementioned nanomaterials there are several other nanoscale
substances that are involved in the water splitting reaction for the generation of
hydrogen. Some of them are listed in Table 1.1.