Newly Emerging Metal–Organic Frameworks (MOF), MXenes and Zeolite …
233
sulfur-containing ligands [111–113]. They fabricated a kind of Zr-DMBN by introducing thiol groups into MOFs. Zr–DMBN could lower Hg concentration to below
0.01 mg/L after 12 h adsorption. Chem et al. reported a kind of sulfur functionalized
MOF (FJI-H12) starting from SCN, Co
2+ , and 2,4,6-tri(1-imidazolyl)-1,3,5-trizaine
(Timt) [114]. Adsorption capability of FJI-H12 could be as high as 439.8 mg/g. Li
and co-workers synthesized isoreticular luminescent MOFs (LMOF-261, 262, and
263) by introducing fluorescent molecules and sulfone functionalized co-linkers into
the framework. The obtained LMOFs were highly water stable and sensitive to Hg,
and the detection limit was as low as 3.3 ppb. Wu et al. reported a kind of rod-like
MOF-5 nanomaterials for U removal. The maximum sorption capability could be
237 mg/g at pH = 5 and 298 K [115]. The dominant sorption mechanism between
U and rod-like MOF-5 was the synergy of surface complexation and electrostatic
interaction.
Besides heavy metal ions, organic pollutants remove by MOFs have also been
extensively investigated. In 2010, Jhung et al. executed the pioneering work on the
applications of MOFs in dyes removal. They used MIL-101, MIL-53, and some modified MOFs for adsorbing MO [116]. High porosity and large pore sizes contribute
to the high adsorption capacity. Specific affinities, such as electrostatic interactions,
also play important roles. Afterward, adsorption of dyes on other MOFs such as
MIL-100(Fe, Cr) was also reported [117]. Apart from the central metals influence on
the adsorption ability of MOFs, Bibi et al. investigated the role of surface conditions
[118]. MOFs have also shown adsorption ability to agrochemicals, such as 2,4-D
[119], MCPP [120], and herbicides [121].
MOF nanosheets have also shown applications in heavy metal ions removal. A
facile operating method was adopted to exfoliate few-layered CoCNSP nanosheets
from the bulk MOFs (Fig. 6a) [122]. Periodically aligned sulfur species were
distributed on the nanosheets. The nanosheets exhibited lateral area of 0.5 μm
(Fig. 6b) and thickness of sub-4.0 nm (Fig. 6c). S···S distance of 0.9476 nm
verified that the obtained CoCNSP nanosheets constituted few layers. CoCNSP
nanosheets displayed excellent heavy metal ions removal in the sequence of Co(II),
Zn(II), Cd(II), Ni(II) Cu(II) < Pb(II) < U(VI) < Hg(II) regardless of singlecomponent and/or multi-component adsorption backgrounds. The uptake capacities of the nanosheets toward Hg(II), U(VI), Pb(II), and Cu(II) were 716, 661,
534, and 325 mg/g, respectively. Even with the ionic strength up to 100 mM,
CoCNSP nanosheets could also maintain high adsorption efficiency in a wide pH
range with good recycling performance. Xu et al. sreported a kind of 2D zinc-based
MOF nanosheets of Zn(Bim)(OAc) with high heavy metals capture (Fig. 6d) [123].
Zn(Bim)(OAc) nanosheets showed an ultrathin 2D structure with lateral length of
more than 2 μm thickness of 7.05 nm (Fig. 6e and f) with highly exposed active
sites. The adsorption capacity for Pb(II) and Cu(II) was 253.8 and 335.57 mg/g,
respectively.
233
sulfur-containing ligands [111–113]. They fabricated a kind of Zr-DMBN by introducing thiol groups into MOFs. Zr–DMBN could lower Hg concentration to below
0.01 mg/L after 12 h adsorption. Chem et al. reported a kind of sulfur functionalized
MOF (FJI-H12) starting from SCN, Co
2+ , and 2,4,6-tri(1-imidazolyl)-1,3,5-trizaine
(Timt) [114]. Adsorption capability of FJI-H12 could be as high as 439.8 mg/g. Li
and co-workers synthesized isoreticular luminescent MOFs (LMOF-261, 262, and
263) by introducing fluorescent molecules and sulfone functionalized co-linkers into
the framework. The obtained LMOFs were highly water stable and sensitive to Hg,
and the detection limit was as low as 3.3 ppb. Wu et al. reported a kind of rod-like
MOF-5 nanomaterials for U removal. The maximum sorption capability could be
237 mg/g at pH = 5 and 298 K [115]. The dominant sorption mechanism between
U and rod-like MOF-5 was the synergy of surface complexation and electrostatic
interaction.
Besides heavy metal ions, organic pollutants remove by MOFs have also been
extensively investigated. In 2010, Jhung et al. executed the pioneering work on the
applications of MOFs in dyes removal. They used MIL-101, MIL-53, and some modified MOFs for adsorbing MO [116]. High porosity and large pore sizes contribute
to the high adsorption capacity. Specific affinities, such as electrostatic interactions,
also play important roles. Afterward, adsorption of dyes on other MOFs such as
MIL-100(Fe, Cr) was also reported [117]. Apart from the central metals influence on
the adsorption ability of MOFs, Bibi et al. investigated the role of surface conditions
[118]. MOFs have also shown adsorption ability to agrochemicals, such as 2,4-D
[119], MCPP [120], and herbicides [121].
MOF nanosheets have also shown applications in heavy metal ions removal. A
facile operating method was adopted to exfoliate few-layered CoCNSP nanosheets
from the bulk MOFs (Fig. 6a) [122]. Periodically aligned sulfur species were
distributed on the nanosheets. The nanosheets exhibited lateral area of 0.5 μm
(Fig. 6b) and thickness of sub-4.0 nm (Fig. 6c). S···S distance of 0.9476 nm
verified that the obtained CoCNSP nanosheets constituted few layers. CoCNSP
nanosheets displayed excellent heavy metal ions removal in the sequence of Co(II),
Zn(II), Cd(II), Ni(II) Cu(II) < Pb(II) < U(VI) < Hg(II) regardless of singlecomponent and/or multi-component adsorption backgrounds. The uptake capacities of the nanosheets toward Hg(II), U(VI), Pb(II), and Cu(II) were 716, 661,
534, and 325 mg/g, respectively. Even with the ionic strength up to 100 mM,
CoCNSP nanosheets could also maintain high adsorption efficiency in a wide pH
range with good recycling performance. Xu et al. sreported a kind of 2D zinc-based
MOF nanosheets of Zn(Bim)(OAc) with high heavy metals capture (Fig. 6d) [123].
Zn(Bim)(OAc) nanosheets showed an ultrathin 2D structure with lateral length of
more than 2 μm thickness of 7.05 nm (Fig. 6e and f) with highly exposed active
sites. The adsorption capacity for Pb(II) and Cu(II) was 253.8 and 335.57 mg/g,
respectively.