Nanomaterials: Surface Functionalization …
423
nanoparticles and porous carbon/CNTs for adsorption of organic dyes. This adsorbent displays best adsorption capability (898 mg/g) towards MG. After adsorption,
nanohybrids are separated easily from the solution using the magnet. [47] functionalized CNTs through a reaction of 1,6- hexane-diamine in magnetic Fe 3 O 4 NPs (MNP)
with carboxyl groups of CNTs with the help of simple solvothermal chemistry. At
solution pH 2.0, the highest adsorption capability for Cr (VI) of MNP/MWCNTs
was seen. [48] modified Carbon nanotubes/Fe 3 O 4 nanomaterials with “mercaptopropyltriethoxysilane (MPTS)” to form a superparamagnetic “MPTS/CNT/Fe 3 O 4 ”
nanomaterial with an improved adsorption capacity (Fig. 10[b]). The surface area,
which is actively calculated for “MPTS/CNT/Fe 3 O 4 ” was seen to be higher than that
of CNT/Fe3O4. Lewis acid-base interactions influenced thiol groups in MPTS having
an intense attraction for heavy metal ions [49]. Therefore, the “MPTS/CNT/Fe 3 O 4 ”
nanomaterial effectively adsorbed heavy metal ions from wastewater. [50] proposed
that cationic (MB) and anionic (MO) dye can be separated by KOH-activated CNTs
having high pore volume (1.61 cm
2 /g) and surface area (534.6 m
2 /g).
The better adsorption capability for MB (400 mg/g) and MO (149 mg/g) onto
A-CNTs was because of large-scale adsorption mechanisms like p-p electron-donor–
acceptor interactions, electrostatic attractions, H-bonding, and pore filling. American
Chemical Society. (B) MPTS-CNTs/Fe3O4 nanocomposites for the separation of Pb
(II) and Hg (II) [48, 51]. The surface functionalization of MWCNT was utilized
to develop stable and uniform nanofluids. Chemical and physical treatment is used
to functionalize MWCNTS. Chemically modified CNTs were dispersed in the base
fluid, which was acetone, and the prepared fluid was called NF-1 (0.2 wt%). The
wrapping performed the physical surface modification of nanotubes by polyethylene
glycol of CNTs. The nanoparticles’ behavior in the base fluid (NF-2, 0.2 wt%) is
optimized by a different nanofluid prepared by the combination of physical and
chemical surface functionalization. The results proved that these nanofluids could
improve the system’s heat transfer coefficient by around 27%.
4.3 Modifications of Graphitic Carbon Nitride (G-C3 N4)
[52] proposed to synthesis a g-C3N4 hydrogel (h-CN) for adsorbing various and
dyes h-CN was found to have a remarkable 99% adsorption efficiency in selectively adsorbing with cationic dyes. The adsorbing capacity of the cationic dyes is
attributed to the h-CN surface charge, analyzed with the help zeta potential. The h-CN
zeta potential was observed to be C3N4 (30–40 mV). Another method to enhance
water pollutant removal potential of g-C3N4 is by modifying the architecture by
applying porosity for improved surface area [53]. Highly electronegative elements
have been used to modify g-C3N4, which has resulted in the adsorption of anionic
dyes or electron-rich pollutants, which resulted in the decomposition of toxic organic
compounds [54].
g-C3N4 is an environment-compatible adsorbent for water pollutants because
of high mechanical and low-cost, thermal and chemical stabilities. More research
423
nanoparticles and porous carbon/CNTs for adsorption of organic dyes. This adsorbent displays best adsorption capability (898 mg/g) towards MG. After adsorption,
nanohybrids are separated easily from the solution using the magnet. [47] functionalized CNTs through a reaction of 1,6- hexane-diamine in magnetic Fe 3 O 4 NPs (MNP)
with carboxyl groups of CNTs with the help of simple solvothermal chemistry. At
solution pH 2.0, the highest adsorption capability for Cr (VI) of MNP/MWCNTs
was seen. [48] modified Carbon nanotubes/Fe 3 O 4 nanomaterials with “mercaptopropyltriethoxysilane (MPTS)” to form a superparamagnetic “MPTS/CNT/Fe 3 O 4 ”
nanomaterial with an improved adsorption capacity (Fig. 10[b]). The surface area,
which is actively calculated for “MPTS/CNT/Fe 3 O 4 ” was seen to be higher than that
of CNT/Fe3O4. Lewis acid-base interactions influenced thiol groups in MPTS having
an intense attraction for heavy metal ions [49]. Therefore, the “MPTS/CNT/Fe 3 O 4 ”
nanomaterial effectively adsorbed heavy metal ions from wastewater. [50] proposed
that cationic (MB) and anionic (MO) dye can be separated by KOH-activated CNTs
having high pore volume (1.61 cm
2 /g) and surface area (534.6 m
2 /g).
The better adsorption capability for MB (400 mg/g) and MO (149 mg/g) onto
A-CNTs was because of large-scale adsorption mechanisms like p-p electron-donor–
acceptor interactions, electrostatic attractions, H-bonding, and pore filling. American
Chemical Society. (B) MPTS-CNTs/Fe3O4 nanocomposites for the separation of Pb
(II) and Hg (II) [48, 51]. The surface functionalization of MWCNT was utilized
to develop stable and uniform nanofluids. Chemical and physical treatment is used
to functionalize MWCNTS. Chemically modified CNTs were dispersed in the base
fluid, which was acetone, and the prepared fluid was called NF-1 (0.2 wt%). The
wrapping performed the physical surface modification of nanotubes by polyethylene
glycol of CNTs. The nanoparticles’ behavior in the base fluid (NF-2, 0.2 wt%) is
optimized by a different nanofluid prepared by the combination of physical and
chemical surface functionalization. The results proved that these nanofluids could
improve the system’s heat transfer coefficient by around 27%.
4.3 Modifications of Graphitic Carbon Nitride (G-C3 N4)
[52] proposed to synthesis a g-C3N4 hydrogel (h-CN) for adsorbing various and
dyes h-CN was found to have a remarkable 99% adsorption efficiency in selectively adsorbing with cationic dyes. The adsorbing capacity of the cationic dyes is
attributed to the h-CN surface charge, analyzed with the help zeta potential. The h-CN
zeta potential was observed to be C3N4 (30–40 mV). Another method to enhance
water pollutant removal potential of g-C3N4 is by modifying the architecture by
applying porosity for improved surface area [53]. Highly electronegative elements
have been used to modify g-C3N4, which has resulted in the adsorption of anionic
dyes or electron-rich pollutants, which resulted in the decomposition of toxic organic
compounds [54].
g-C3N4 is an environment-compatible adsorbent for water pollutants because
of high mechanical and low-cost, thermal and chemical stabilities. More research