438
prepared a bismuth cationic metal–organic framework to remove methylene blue
and rhodamine B dyes. The designed metal–organic framework could adsorb both
dyes, but a quantitative analysis was not reported. Abbasi et al. (2015) coated silk
fiber’s surface by a thin film of Zn metal–organic framework and then used it for the
adsorption of methyl orange and morphine.
Carbon Nanotubes and Graphene Oxide-Incorporated Adsorbents
Graphene and carbon nanotubes with large external surface area, specific morphology, and well-formed mesopores exhibit a great potential for the removal of various
types of environmental contaminants (Ren et al. 2011; Saleh et al. 2011). Graphite
oxide is a layered material composed of graphene oxide sheets with oxygenated
functional groups on their basal edges and planes. Both graphene and carbon nanotubes are considered as excellent adsorbents for the treatment of dye-contaminated
water, benefiting from desirable physical and chemical stability, proper mechanical
properties, high selectivity, and high specific surface area. Broad experimental studies have been performed on the adsorption of inorganic or organic pollutants on
graphene and carbon nanotubes (Li et al. 2013a). Carbon nanotube-based hybrids
are advanced materials that have received much attention due to their outstanding
structures and mechanical properties (Pradhan et al. 2015).
The use of graphene oxide and carbon nanotubes in the preparation of metal–
organic framework hybrid materials is a promising way to obtain novel adsorbent
for wastewater treatment (Li et al. 2013b). The incorporation of graphene oxide and
carbon nanotubes can improve metal–organic framework formation by preventing
their aggregation, enhancing the dispersive forces in the structure of metal–organic
frameworks, and controlling physicochemical properties (size, structure, and morphology) of metal–organic framework (Petit and Bandosz 2012). Abdi et al. synthesized ZIF-8 as a metal–organic framework and its graphene oxide and carbon
nanotube-based hybrid nanocomposites as adsorbents for the removal of malachite
green dye from wastewater. The results disclosed that the hybrid nanocomposites
exhibited higher dye removal rates than the sole metal–organic framework (Abdi
et al. 2017).
The significance of adding graphene oxide to the chitin matrix is useful not only
in reinforcing the composite but also in improving the adsorption versatility due to
the different chemical nature of the two materials. Obtaining a solid-like gel from
the two powders has introduced the hybrid as a promising adsorbent for heterogeneous phase wastewater treatment (Kyzas et al. 2011). González et al. synthesized
chitin/graphene oxide hybrid gels and then used it for the adsorption of the basic
and acidic dyes (González et al. 2015).
Liu et al. (2015) prepared MnO 2 /graphene–carbon nanotube hybrid adsorbent for
the adsorption of methyl orange. The results showed that the hybrid adsorbent
exhibited an excellent adsorption capacity toward methyl orange.
Jiao et al. (2015) synthesized graphene oxide/Fe 3 O 4 nanohybrids for rapid and
effective adsorption of organic dyes. Ai and Jiang (2012) prepared self-assembled
R. M. Moattari and T. Mohammadi
prepared a bismuth cationic metal–organic framework to remove methylene blue
and rhodamine B dyes. The designed metal–organic framework could adsorb both
dyes, but a quantitative analysis was not reported. Abbasi et al. (2015) coated silk
fiber’s surface by a thin film of Zn metal–organic framework and then used it for the
adsorption of methyl orange and morphine.
Carbon Nanotubes and Graphene Oxide-Incorporated Adsorbents
Graphene and carbon nanotubes with large external surface area, specific morphology, and well-formed mesopores exhibit a great potential for the removal of various
types of environmental contaminants (Ren et al. 2011; Saleh et al. 2011). Graphite
oxide is a layered material composed of graphene oxide sheets with oxygenated
functional groups on their basal edges and planes. Both graphene and carbon nanotubes are considered as excellent adsorbents for the treatment of dye-contaminated
water, benefiting from desirable physical and chemical stability, proper mechanical
properties, high selectivity, and high specific surface area. Broad experimental studies have been performed on the adsorption of inorganic or organic pollutants on
graphene and carbon nanotubes (Li et al. 2013a). Carbon nanotube-based hybrids
are advanced materials that have received much attention due to their outstanding
structures and mechanical properties (Pradhan et al. 2015).
The use of graphene oxide and carbon nanotubes in the preparation of metal–
organic framework hybrid materials is a promising way to obtain novel adsorbent
for wastewater treatment (Li et al. 2013b). The incorporation of graphene oxide and
carbon nanotubes can improve metal–organic framework formation by preventing
their aggregation, enhancing the dispersive forces in the structure of metal–organic
frameworks, and controlling physicochemical properties (size, structure, and morphology) of metal–organic framework (Petit and Bandosz 2012). Abdi et al. synthesized ZIF-8 as a metal–organic framework and its graphene oxide and carbon
nanotube-based hybrid nanocomposites as adsorbents for the removal of malachite
green dye from wastewater. The results disclosed that the hybrid nanocomposites
exhibited higher dye removal rates than the sole metal–organic framework (Abdi
et al. 2017).
The significance of adding graphene oxide to the chitin matrix is useful not only
in reinforcing the composite but also in improving the adsorption versatility due to
the different chemical nature of the two materials. Obtaining a solid-like gel from
the two powders has introduced the hybrid as a promising adsorbent for heterogeneous phase wastewater treatment (Kyzas et al. 2011). González et al. synthesized
chitin/graphene oxide hybrid gels and then used it for the adsorption of the basic
and acidic dyes (González et al. 2015).
Liu et al. (2015) prepared MnO 2 /graphene–carbon nanotube hybrid adsorbent for
the adsorption of methyl orange. The results showed that the hybrid adsorbent
exhibited an excellent adsorption capacity toward methyl orange.
Jiao et al. (2015) synthesized graphene oxide/Fe 3 O 4 nanohybrids for rapid and
effective adsorption of organic dyes. Ai and Jiang (2012) prepared self-assembled
R. M. Moattari and T. Mohammadi