In the presence of
melamine and block copolymers, namely, F108,
F127, and P123, nitrogen-doped nanoporous carbon nanospheroids (N@CNSs)
were synthesized by the hydrothermal process. The F127-modified sample
(CNF127) exhibits the maximum Brunauer–Emmett–Teller
(BET) surface area of 773.4 m
2
/g with a pore volume of
0.877 cm
3
/g. The microstructural study reveals that nanospheroids
of size 50–200 nm were aggregated together to form a chainlike
structure for all triblock copolymer-modified samples. The X-ray photoelectron
spectroscopy study shows the binding energies of 398.33 and 400.7
eV attributed to sp
2
(C–N=C)- and sp
3
(C–N)-hybridized nitrogen-bonded carbons, respectively.
The synthesized N@CNS samples showed selective adsorption of organic
dye methylene blue (MB) in the presence of methyl orange (MO) as well
as Pb(II) ion removal from contaminated water. The adsorptions for
MB and Pb(II) ions followed pseudo-first-order and pseudo-second-order
kinetic models, respectively. The sample CNF127 showed the highest
adsorption of 73 and 99.82 mg/g for MB and Pb(II) adsorptions, respectively.
The adsorption capacity for MB of the copolymer-modified samples follows
the order CNF127 > CNP123 > CNF108, which corroborated with
the mesoporosity
as well as nitrogen content of the corresponding samples. The maximum
% adsorption of Pb(II) follows the order CNF127 (99.82%) > CNF108
(98.74%) > CNP123 (91.82%), and this trend is attributed to the
BET
surface area of the corresponding samples. This study demonstrates
multicomponent removal of water pollutants, both organic dyes and
inorganic toxic metal ions.