Thiol-Functionalized Pores via Post-Synthesis Modification in a Metal

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Thiol-Functionalized Pores via Post-Synthesis Modification in a Metal−Organic Framework with Selective Removal of Hg(II) in Water Gao-Peng Li,†,# Kun Zhang,‡,# Peng-Feng Zhang,† Wei-Ni Liu,† Wen-Quan Tong,† Lei Hou,*,† and Yao-Yu Wang*,† †

Inorg. Chem. Downloaded from pubs.acs.org by UNIV OF NEW ENGLAND on 02/14/19. For personal use only.

Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi’an 710127, P. R. China ‡ School of Textile Science and Engineering, Xi’an Polytechnic University, Xi’an 710048, P. R. China S Supporting Information *

ABSTRACT: Owing to the rapid increase of Hg(II) ions in water resources, the design and development of new adsorbents for Hg(II) removal are becoming a significant challenge in environmental protection. Herein, a thiolfunctionalized metal−organic framework (SH-MiL-68(In)) was successfully prepared through a post-synthesis modification procedure, and the framework intactness and porosity were well maintained after this process. SH-MiL-68(In) exhibited selective adsorption performance for Hg(II) ions in water. Meanwhile, SH-MiL-68(In) also shows a high adsorption capacity (450 mg g−1), large adsorption rate (rate constant k2 = 1.25 g mg−1 min−1), and good recycling of adsorption capacity toward Hg(II) ions. The excellent adsorption performance resulted from the strong binding interactions between -SH soft basic groups and Hg(II) soft acidic ions.

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ions.33−36 Meanwhile, in order to produce effective MOF adsorbents with strong binding affinity toward Hg(II) ions, the ligands have been decorated by specific functional groups, such as thiol and amino groups.37,38 However, these functionalized ligands in many reported MOFs are hard to prepare, and moreover, those functional sites rather coordinate with the metal centers instead of being retained on the channel surface freely. Therefore, using the post-synthesis modification (PSM) procedure would be an ideal method to optimize the guest− host properties of MOFs and broaden the application area of MOFs as well.39,40 Herein, through a PSM method, one water-stable thiolfunctionalized MOF was prepared, which can remove Hg(II) ions in water efficiently. To obtain this MOF, one water-stable MOF, NH2-MiL-68(In), with the modifiable -NH2 groups in ligands was selected.41 The three-dimensional NH2-MiL68(In) has two different channels with window openings of 6 and 16 Å.42 The exposed -NH2 groups in channels provide accessible sites for the surface functionalization via combining this group with aldehyde/carboxylic acid molecules.43,44 Treating NH2-MiL-68(In) through a PSM strategy, the thiolfunctionalized MOF, SH-MiL-68(In), was prepared. During the process, the mercaptoacetic acid was fixed on the channel walls of NH2-Mil-68(In) via generating aramid groups. The Hg(II) adsorption experiments indicated that SH-MiL-68(In) possessed high selective adsorption capacity and good

INTRODUCTION Heavy metal ions in water systems are causing great damage to human life and other organisms due to their severe toxicity and carcinogenicity.1−3 Specifically, Hg(II) ion pollution is regarded as an important concern because it is very harmful to our nervous/immune system, kidneys, and brain.4−6 Meanwhile, the methyl mercury obtained from the microbial biomethylation of Hg(II) usually damages the developing brain when it is deposited in the central nervous system.7,8 Considering Hg(II) ions in water is the main contact source, the most allowable Hg(II) concentration is 30 nM in drinking water according to the standard of World Health Organization (WHO).9 Therefore, the preparation of highly efficient adsorbents for Hg(II) capture is urgently needed. Now, many effective sorbent materials, such as carbon materials,10 biomass,11 nanoparticles,12 and chelating polymers13 have been developed for Hg(II) capture; however, those sorbents are subject to some challenges, for example, small adsorption amount, low selectivity, weak adsorption affinity, slow kinetics, and so on. It is an urgent need to design and synthesize more efficient adsorbents with dispersed adsorption sites and strong binding interactions with Hg(II) ions in water. Metal−organic frameworks (MOFs), consisting of organic units and metal ions/clusters,14−26 have displayed great prospects in applications, including selective adsorption,27,28 catalysis,29,30 and sensing.31,32 The high specific surface areas and orderly distributed functional sites in MOFs enable them possibly to adsorb the heavy metal ions, and some known MOFs possessed good adsorption performance for metal © XXXX American Chemical Society

Received: December 17, 2018

A

DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry Scheme 1. Schematic Representation of SH-MiL-68(In) Synthesis

Figure 1. (a) PXRD patterns; (b) FT-IR patterns; (c) N2 adsorption isotherms at 77 K of NH2-MiL-68(In) and SH-MiL-68(In).

recycling stability, demonstrating considerable application potential for removing Hg(II) in water.

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removal efficiency (%) =

Materials and General Methods. All reagents and solvents in our experiments were purchased, and the characterization methods are listed in Section S1 in Supporting Information. Preparation of NH2-MIL-68(In). One reported procedure was used to prepare NH2-MIL-68(In).43 NH2-H2BDC (46 mg, 0.25 mmol), benzoic acid (8 mg, 0.06 mmol), and pyridine (40 μL, 0.5 mmol) were dissolved in 1.5 mL of DMF in a 10 mL capped vial, and then 1 mL of DMF contained In(NO3)3 (105 mg, 0.35 mmol) was added. After sonication for 5 min, the mixture was heated at 125 °C in the oven for 2.5 h. It was cooled to room temperature, and the resulting light yellow powders were obtained by centrifugation and washing with ethanol. Preparation of SH-MIL-68(In). NH2-MIL-68(In) (50 mg) was immersed in CH2Cl2 (2 mL) containing mercaptoacetic acid (MAA) (26 mg, 0.28 mmol). The mixture was left at room temperature to react for 12 h, and then the solids were isolated via centrifugation and washed thoroughly with MeOH. After further soaking in MeOH, the yellow solids were isolated via centrifugation. Adsorption Studies. Ten milligrams of SH-MiL-68(In) was added into a 10 mL water solution of Hg(II) (10 mg L−1). Next, HCl/NaOH solution (0.1 M) was used to regulate the solution pH. The adsorption capacity qt (mg g−1) and removal efficiency were obtained by the equations:

(C0 − Ct )V m

(2)

in which the C0 (mg L−1), Ce (mg L−1), and Ct (mg L−1) present the concentrations of Hg(II) at beginning, equilibrium, and t time, respectively. V (L) and m (g) are the solution volume and adsorbent weight, respectively. The effect of the exposure time on Hg(II) capture in SH-MiL68(In) was investigated by adding SH-MiL-68(In) (20 mg) into the water solution of Hg(II) (20 mL, 20 mg L−1) and followed by taking out samples at a certain time interval and subjecting them to ICP determination.

EXPERIMENTAL SECTION

qt =

C0 − Ce × 100% C0

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RESULTS AND DISCUSSION Preparation and Characterization. Using organic ligands contained thiol functional groups to construct porous frameworks for Hg(II) removal has been proven to be a powerful strategy.3,37,45 Herein, a stable SH-functionalized MOF, SH-MiL-68(In), was synthesized by reacting NH2-MiL68(In) with MAA in a CH2Cl2 solution at room temperature for 12 h (Scheme 1). The well matched powder X-ray diffraction (PXRD) patterns between SH-MiL-68(In) and NH2-MiL-68(In) suggest the same framework structure (Figure 1a). The mercaptoacetylation of NH2-MiL-68(In) to yield SH-MiL-68(In) was evidenced by Fourier transform infrared spectroscopy (FT-IR) (Figure 1b). The absorption peak at 2552 cm−1 is designated to be a sulfhydryl group,37 and meanwhile, the peaks of scissoring CO, -NH-, and C−N in the amide group can be observed at 1634, 1593, and 1413 cm−1, respectively, indicating the successful grafting of MAA

(1) B

DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry onto the MOF framework via forming amide bonds.46,47 Meanwhile, the elemental analysis result of SH-MiL-68(In) gave a N/S ratio of 4.38/3.24. This deduction is further demonstrated by energy dispersive spectroscopy (EDS) analysis of different elements (Figure S1). The Brunauer− Emmett−Teller (BET) surface area for SH-MiL-68(In) (287 cm2 g−1) is far lower than that of NH2-MiL-68(In) (469.29 cm2 g−1) (Figure 1c), resulting from the decreased free voids due to the occupation of bulky functional groups in SH-MiL68(In). The modification of MAA also leads to a smaller pore size distribution of about 6.1 Å for SH-MiL-68(in) (Figure S2). In addition, PXRD confirmed the good stability of SHMiL-68(In) that was treated with different pH of solutions (Figure S3). Effect of pH. Due to the acidity of common industrial wastewater, high adsorption capacity under acidic conditions is required for an adsorbent. The effect of pH on Hg(II) capture in SH-MiL-68(In) was investigated (Figure 2). The Hg(II)

Figure 3. Selectivity of SH-MiL-68(In) for Hg(II) compared to other metal ions.

2 min, indicating the fast adsorption process of Hg(II) in SHMil-68(In). Then, the kinetic data were fitted with a pseudosecond-order kinetic equation (Section S2-1 in Supporting Information) to study the kinetic mechanism. The high correlation coefficient (R2 = 0.9999) implies that the adsorption behavior well follows this mode (Figure 4b). Fast kinetics (k2) of 1.25 g mg−1 min−1 was determined at the same time, which can be comparable with the values in other traditional Hg(II) sorbents under similar situations.52−55 The fast Hg(II) removal rate possible results from the strong affinity between Hg(II) and a large number of sulfur species in SH-MiL-68(In). Adsorption Isotherms. To estimate the maximum Hg(II) adsorption capacity in SH-MiL-68(In), adsorption isotherms were performed at pH = 4 in a series of Hg(II) solutions with the concentration range of 10−120 mg L−1 (Figure 5a). The adsorption amount in SH-MiL-68(In) increased sharply and then reached saturation with a maximum value of 450.36 mg g−1. Although this value is lower than those in PAF-1 (1014 mg g−1)56 and NENU-401 (∼600 mg g−1),57 it greatly surpasses the values for other MOF adsorbents, such as MFC-S (282 mg g−1),38 Zr-L4 (322 mg g−1), and MIL-101-thymine (59.28 mg g−1).58 Meanwhile, compared to the previously reported thiol/ thio-functionalized porous materials, SH-MiL-68(In) has a simpler synthesis process.38 For comparison, the adsorption curve of Hg(II) in NH2-MiL-68(In) was also measured at pH = 4, which shows a significantly decreased adsorption amount relative to SH-MiL-68(In) (Figure S4). Therefore, the modification of the framework by introducing MAA groups provides a crucial contribution for the increased capacity of Hg(II) removal in SH-MiL-68(In). Notably, the adsorption data of Hg(II) in NH2-MiL-68(In) can be fitted by the Langmuir model with a high correlation coefficient (R2 = 0.9989) (Figure 5b) (Section S2-2 in Supporting Information), indicating a monolayer adsorption process.59 Adsorption Mechanism. To analyze the adsorption mechanism of SH-MiL-68(In) for Hg(II) capture, X-ray photoelectron spectroscopy (XPS) analysis was performed (Figure 6a). The inclusion of Hg(II) in Hg(II)@SH-MiL68(In) was confirmed by the appearance of the XPS signal from Hg 4f. Meanwhile, there is a higher binding energy shift (1.2 eV) for S 2p in Hg(II)@MiL-68(In) compared to SHMiL-68(In) (Figure 6b). However, the N 1s and O 1s XPS spectra for Hg(II)@SH-MiL-68(In) show almost no changes (Figure S5), excluding the important interactions between Hg(II) ions and N or O atoms. We inferred that the interactions between Hg(II) and S species should be

Figure 2. Effect of pH on Hg(II) adsorption in SH-MiL-68(In).

adsorption amount in SH-MiL-68(In) increased substantially from pH = 1 to 4, which is due to the coordination influence between H+ ions and -SH groups in the ionized SH-MiL68(In). The removal efficiency is highest at pH = 4 and then gradually decreased with the pH increasing. As we known, both Hg(II) and Hg(OH)+ coexist in water at pH = 3−6.47.48 When pH > 6.47, mercury ions mainly exist as Hg(OH)2.49 With the pH increasing, the hydrolysis degree of Hg(II) is enhanced, and the radii of hydrated Hg(OH)+ and Hg(OH)2 (about 8.2 Å) are slightly bigger than the aperture size of SHMiL-68(In) (about 6.1 Å), reducing the Hg(II) removal via adsorption. Selective Adsorption. The capture selectivity for Hg(II) was assessed in the solution with other coexisting ions, such as Mg(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II). For this experiment, 10 mg of SH-MiL-68(In) was dispersed in a water solution containing Hg(II) (10 mg L−1), and above each metal ion (10 mg L−1), and then stirred for 30 min. The removal efficiency of Hg(II) at pH = 4 is >99%, but there was no obvious adsorption for other metal ions (Figure 3). Therefore, SH-MiL-68(In) is very appropriate to selectively remove Hg(II) in water, which can be illustrated by the soft− hard acid−base principle between Hg(II) and -SH groups.50,51 Adsorption Kinetics. In view of the adsorption kinetics providing information on the capture rate and reaction pathways of adsorbates, it is a key parameter for evaluating the adsorption mechanism and practical applications. The result in Figure 4a shows that >98% Hg(II) can be removed in C

DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry

Figure 4. (a) The effect of contact time on the Hg(II) adsorption in SH-MiL-68(In); (b) the pseudo-second-order kinetic plot for the Hg(II) adsorption in SH-MiL-68(In).

Figure 5. Adsorption isotherm of Hg(II) (a) along with the linear regression by fitting the equilibrium adsorption data with the Langmuir adsorption model (b).

Figure 6. (a) XPS spectra for SH-MiL-68(In) before and after Hg(II) adsorption; (b) comparison of S 2p XPS spectra of SH-MiL-68(In) before and after Hg(II) adsorption.

Stability and Reusability. The regeneration of SH-MiL68(In) can be achieved through washing the adsorbent with 0.01 M HCl, 0.1% thiourea, and deionized water, respectively. The regenerated SH-MiL-68(In) shows almost no change in Hg(II) adsorption capacity after five runs of recycling (Figure 7). Meanwhile, PXRD confirmed the stability of SH-MiL68(In) after recycling (Figure S6). These results indicated the good stability and recycling of SH-MiL-68(In) during the adsorption and desorption processes.

responsible for the excellent performance. This inference is supported by the hard−soft acid−base principle: Hg(II) as the soft Lewis acid prefers to combine with the soft Lewis base S.50,51 Therefore, in this adsorption process, Hg(II) may replace the H atoms in -SH groups via a proton exchange reaction. If this hypothesis is valid, the pH of reaction system would decrease correspondingly. For verifying this hypothesis, we monitored the changes of pH before and after the Hg(II) adsorption process, and the result shows a decreased pH from 4.14 to 2.76 after Hg(II) was adsorbed. Therefore, the adsorption mechanism in SH-MiL-68(In) may be described by the reaction equation:

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CONCLUSIONS In conclusion, a thiol-functionalized MOF was successfully built through post-synthesis modification, which shows reversible Hg(II) adsorption in water with high selectivity

‐SH + Hg 2 + + 2Cl− → ‐S‐Hg + + H+ + 2Cl− D

DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry

Modified Covalent Organic Frameworks for Efficient and Effective Mercury Removal. J. Am. Chem. Soc. 2017, 139, 2786−2793. (4) Halder, S.; Mondal, J.; Ortega-Castro, J.; Frontera, A.; Roy, P. A Ni-based MOF for selective detection and removal of Hg2+ in aqueous medium: a facile strategy. Dalton Trans. 2017, 46, 1943−1950. (5) Harris, H. H.; Pickering, I. J.; George, G. N. The chemical form of mercury in fish. Science 2003, 301, 1203. (6) Luo, F.; Chen, J. L.; Dang, L. L.; Zhou, W. N.; Lin, H. L.; Li, J. Q.; Liu, S. J.; Luo, M. B. High-performance Hg2+ removal from ultralow-concentration aqueous solution using both acylamide- and hydroxyl-functionalized metal-organic framework. J. Mater. Chem. A 2015, 3, 9616−9620. (7) Trasande, L.; Landrigan, P. J.; Schechter, C. Public health and economic consequences of methyl mercury toxicity to the developing brain. Environ. Health Perspect. 2005, 113, 590−596. (8) Hu, P. P.; Liu, N.; Wu, K. Y.; Zhai, L. Y.; Xie, B. P.; Sun, B.; Duan, W. J.; Zhang, W. H.; Chen, J. X. Successive and Specific Detection of Hg2+ and I− by a DNA@MOF Biosensor: Experimental and Simulation Studies. Inorg. Chem. 2018, 57, 8382−8389. (9) Zhang, L.; Li, T.; Li, B.; Li, J.; Wang, E. Carbon nanotube-DNA hybrid fluorescent sensor for sensitive and selective detection of mercury(II) ion. Chem. Commun. 2010, 46, 1476−1478. (10) Huang, C. P.; Blankenship, D. W. The removal of mercury(II) from dilute aqueous solution by activated carbon. Water Res. 1984, 18, 37−46. (11) Tuzen, M.; Sari, A.; Mendil, D.; Soylak, M. Biosorptive removal of mercury(II) from aqueous solution using lichen (Xanthoparmelia conspersa) biomass: Kinetic and equilibrium studies. J. Hazard. Mater. 2009, 169, 263−270. (12) Lu, F.; Astruc, D. Nanomaterials for removal of toxic elements from water. Coord. Chem. Rev. 2018, 356, 147−164. (13) Miretzky, P.; Cirelli, A. F. Hg(II) removal from water by chitosan and chitosan derivatives: A review. J. Hazard. Mater. 2009, 167, 10−23. (14) Mon, M.; Bruno, R.; Ferrando-Soria, J.; Armentano, D.; Pardo, E. Metal-organic framework technologies for water remediation: towards a sustainable ecosystem. J. Mater. Chem. A 2018, 6, 4912− 4947. (15) Zhao, J.; Dong, W.-W.; Wu, Y.-P.; Wang, Y.-N.; Wang, C.; Li, D.-S.; Zhang, Q.-C. Two (3,6)-connected porous metal-organic frameworks based on linear trinuclear [Co3(COO)6] and paddlewheel dinuclear [Cu2(COO)4] SBUs: gas adsorption, photocatalytic behaviour, and magnetic properties. J. Mater. Chem. A 2015, 3, 6962−6969. (16) Fu, H.-R.; Yan, L.-B.; Wu, N.-T.; Ma, L.-F.; Zang, S.-Q. Dualemission MOF⊃dye sensor for ratiometric fluorescence recognition of RDX and detection of a broad class of nitro-compounds. J. Mater. Chem. A 2018, 6, 9183−9191. (17) Zhang, M.; Zhou, W.; Pham, T.; Forrest, K. A.; Liu, W.; He, Y.; Wu, H.; Yildirim, T.; Chen, B.; Space, B.; Pan, Y.; Zaworotko, M. J.; Bai, J. Fine Tuning of MOF-505 Analogues To Reduce Low-Pressure Methane Uptake and Enhance Methane Working Capacity. Angew. Chem., Int. Ed. 2017, 56, 11426−11430. (18) Du, M.; Li, C. P.; Chen, M.; Ge, Z. W.; Wang, X.; Wang, L.; Liu, C. S. Divergent kinetic and thermodynamic hydration of a porous Cu(II) coordination polymer with exclusive CO2 sorption selectivity. J. Am. Chem. Soc. 2014, 136, 10906−9. (19) Wu, Y. P.; Zhou, W.; Zhao, D. J.; Dong, W. W.; Lan, Y. Q.; Li, D. S.; Sun, C.; Bu, X. Surfactant-Assisted Phase-Selective Synthesis of New Cobalt MOFs and Their Efficient Electrocatalytic Hydrogen Evolution Reaction. Angew. Chem., Int. Ed. 2017, 56, 13001−13005. (20) Xu, G. W.; Wu, Y. P.; Dong, W. W.; Zhao, J.; Wu, X. Q.; Li, D. S.; Zhang, Q. A Multifunctional Tb-MOF for Highly Discriminative Sensing of Eu3+/Dy3+ and as a Catalyst Support of Ag Nanoparticles. Small 2017, 13, 1602996. (21) Wen, G.-X.; Wu, Y.-P.; Dong, W.-W.; Zhao, J.; Li, D.-S.; Zhang, J. An Ultrastable Europium(III)-Organic Framework with the Capacity of Discriminating Fe2+/Fe3+ Ions in Various Solutions. Inorg. Chem. 2016, 55, 10114−10117.

Figure 7. Hg(II) removal by recycled SH-MiL-68(In) (pH = 4).

and adsorption capacity (449.37 mg g−1) and fast kinetics (k2 = 1.25 g mg−1 min−1). SH-MiL-68(In) also possesses good stability and reusability. Mechanism research showed that the coordination between the Hg(II) ions and -SH groups through replacing the H atoms in -SH groups plays a leading role in the adsorption process. The excellent efficiency for selective Hg(II) adsorption in this material make it very useful for Hg(II) removal in water.

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.8b03505. Detailed characterization method, calculation formulas, EDS analysis, PXRD patterns, and XPS spectra (PDF)

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AUTHOR INFORMATION

Corresponding Authors

*(L.H.) E-mail: [email protected]. *(Y.-Y.W.) E-mail: [email protected]. ORCID

Lei Hou: 0000-0002-2874-9326 Yao-Yu Wang: 0000-0002-0800-7093 Author Contributions #

G.-P.L. and K.Z. contributed equally to this work.

Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by the National Science Foundation of China (Grants 21531007 and 21871220), the Natural Science Basic Research Plan in Shaanxi Province of China (Program No. 2018JQ2026).

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REFERENCES

(1) Li, M.; Gou, H.; Al-Ogaidi, I.; Wu, N. Nanostructured Sensors for Detection of Heavy Metals: A Review. ACS Sustainable Chem. Eng. 2013, 1, 713−723. (2) Aragay, G.; Pons, J.; Merkoci, A. Recent Trends in Macro-, Micro-, and Nanomaterial-Based Tools and Strategies for HeavyMetal Detection. Chem. Rev. 2011, 111, 3433−3458. (3) Sun, Q.; Aguila, B.; Perman, J.; Earl, L. D.; Abney, C. W.; Cheng, Y.; Wei, H.; Nguyen, N.; Wojtas, L.; Ma, S. Postsynthetically E

DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry (22) Zhou, Z.-H.; Dong, W.-W.; Wu, Y.-P.; Zhao, J.; Li, D.-S.; Wu, T.; Bu, X.-h. Ligand-Controlled Integration of Zn and Tb by Photoactive Terpyridyl-Functionalized Tricarboxylates as Highly Selective and Sensitive Sensors for Nitrofurans. Inorg. Chem. 2018, 57, 3833−3839. (23) Zeng, M.-H.; Wang, Q.-X.; Tan, Y.-X.; Hu, S.; Zhao, H.-X.; Long, L.-S.; Kurmoo, M. Rigid Pillars and Double Walls in a Porous Metal-Organic Framework: Single-Crystal to Single-Crystal, Controlled Uptake and Release of Iodine and Electrical Conductivity. J. Am. Chem. Soc. 2010, 132, 2561−2563. (24) Yin, Z.; Zhou, Y.-L.; Zeng, M.-H.; Kurmoo, M. The concept of mixed organic ligands in metal-organic frameworks: design, tuning and functions. Dalton Trans. 2015, 44, 5258−5275. (25) Zeng, M. H.; Yin, Z.; Tan, Y. X.; Zhang, W. X.; He, Y. P.; Kurmoo, M. Nanoporous cobalt(II) MOF exhibiting four magnetic ground states and changes in gas sorption upon post-synthetic modification. J. Am. Chem. Soc. 2014, 136, 4680−4688. (26) Zhang, W.-X.; Liao, P.-Q.; Lin, R.-B.; Wei, Y.-S.; Zeng, M.-H.; Chen, X.-M. Metal cluster-based functional porous coordination polymers. Coord. Chem. Rev. 2015, 293−294, 263−278. (27) Li, X.-Y.; Li, Y.-Z.; Yang, Y.; Hou, L.; Wang, Y.-Y.; Zhu, Z. Efficient light hydrocarbon separation and CO2 capture and conversion in a stable MOF with oxalamide-decorated polar tubes. Chem. Commun. 2017, 53, 12970−12973. (28) He, C. T.; Ye, Z. M.; Xu, Y. T.; Zhou, D. D.; Zhou, H. L.; Chen, D.; Zhang, J. P.; Chen, X. M. Hyperfine adjustment of flexible pore-surface pockets enables smart recognition of gas size and quadrupole moment. Chem. Sci. 2017, 8, 7560−7565. (29) Shi, Y.; Zhang, B. Recent advances in transition metal phosphide nanomaterials: synthesis and applications in hydrogen evolution reaction. Chem. Soc. Rev. 2016, 45, 1529−41. (30) Li, Y.-Z.; Wang, H.-H.; Yang, H.-Y.; Hou, L.; Wang, Y.-Y.; Zhu, Z.-H. An Uncommon Carboxyl-Decorated Metal-Organic Framework with Selective Gas Adsorption and Catalytic Conversion of CO2. Chem. - Eur. J. 2018, 24, 865−871. (31) Kreno, L. E.; Leong, K.; Farha, O. K.; Allendorf, M.; Van Duyne, R. P.; Hupp, J. T. Metal-organic framework materials as chemical sensors. Chem. Rev. 2012, 112, 1105−25. (32) Li, G. P.; Liu, G.; Li, Y. Z.; Hou, L.; Wang, Y. Y.; Zhu, Z. Uncommon Pyrazoyl-Carboxyl Bifunctional Ligand-Based Microporous Lanthanide Systems: Sorption and Luminescent Sensing Properties. Inorg. Chem. 2016, 55, 3952−3959. (33) Xue, H.; Chen, Q.; Jiang, F.; Yuan, D.; Lv, G.; Liang, L.; Liu, L.; Hong, M. A regenerative metal-organic framework for reversible uptake of Cd(II): from effective adsorption to in situ detection. Chem. Sci. 2016, 7, 5983−5988. (34) Yu, C.; Shao, Z.; Hou, H. A functionalized metal-organic framework decorated with O-groups showing excellent performance for lead(II) removal from aqueous solution. Chem. Sci. 2017, 8, 7611−7619. (35) Zheng, T. T.; Zhao, J.; Fang, Z. W.; Li, M. T.; Sun, C. Y.; Li, X.; Wang, X. L.; Su, Z. M. A luminescent metal organic framework with high sensitivity for detecting and removing copper ions from simulated biological fluids. Dalton Trans. 2017, 46, 2456−2461. (36) Shokouhfar, N.; Aboutorabi, L.; Morsali, A. Improving the capability of UiO-66 for Cr(VI) adsorption from aqueous solutions by introducing the isonicotinate N-Oxide as the functional group. Dalton Trans. 2018, 47, 14549−14555. (37) Yee, K. K.; Reimer, N.; Liu, J.; Cheng, S. Y.; Yiu, S. M.; Weber, J.; Stock, N.; Xu, Z. Effective mercury sorption by thiol-laced metalorganic frameworks: in strong acid and the vapor phase. J. Am. Chem. Soc. 2013, 135, 7795−7798. (38) Huang, L.; He, M.; Chen, B.; Hu, B. A mercapto functionalized magnetic Zr-MOF by solvent-assisted ligand exchange for Hg2+ removal from water. J. Mater. Chem. A 2016, 4, 5159−5166. (39) Yin, Z.; Wan, S.; Yang, J.; Kurmoo, M.; Zeng, M.-H. Recent advances in post-synthetic modification of metal-organic frameworks: New types and tandem reactions. Coord. Chem. Rev. 2019, 378, 500− 512.

(40) Yin, Z.; Wang, Q.-X.; Zeng, M.-H. Iodine Release and Recovery, Influence of Polyiodide Anions on Electrical Conductivity and Nonlinear Optical Activity in an Interdigitated and Interpenetrated Bipillared-Bilayer Metal-Organic Framework. J. Am. Chem. Soc. 2012, 134, 4857−4863. (41) Liang, R.; Shen, L.; Jing, F.; Wu, W.; Qin, N.; Lin, R.; Wu, L. NH2-mediated indium metal-organic framework as a novel visiblelight-driven photocatalyst for reduction of the aqueous Cr(VI). Appl. Catal., B 2015, 162, 245−251. (42) Wu, L.; Xue, M.; Qiu, S.-L.; Chaplais, G.; Simon-Masseron, A.; Patarin, J. Amino-modified MIL-68(In) with enhanced hydrogen and carbon dioxide sorption enthalpy. Microporous Mesoporous Mater. 2012, 157, 75−81. (43) Peng, Y.; Zhao, M.; Chen, B.; Zhang, Z.; Huang, Y.; Dai, F.; Lai, Z.; Cui, X.; Tan, C.; Zhang, H. Hybridization of MOFs and COFs: A New Strategy for Construction of MOF@COF Core-Shell Hybrid Materials. Adv. Mater. 2018, 30, 1705454. (44) Yang, H.; Zhang, X.; Zhang, G.; Fei, H. An alkaline-resistant Ag(I)-anchored pyrazolate-based metal-organic framework for chemical fixation of CO2. Chem. Commun. 2018, 54, 4469−4472. (45) Ding, L.; Luo, X.; Shao, P.; Yang, J.; Sun, D. Thiolfunctionalized Zr-based metal-organic framework for capture of Hg(II) through a proton exchange reaction. ACS Sustainable Chem. Eng. 2018, 6, 8494−8502. (46) Bano, S.; Mahmood, A.; Kim, S.-J.; Lee, K.-H. Graphene oxide modified polyamide nanofiltration membrane with improved flux and antifouling properties. J. Mater. Chem. A 2015, 3, 2065−2071. (47) Yang, L.; Jiang, W.; Qiu, L.; Jiang, X.; Zuo, D.; Wang, D.; Yang, L. One pot synthesis of highly luminescent polyethylene glycol anchored carbon dots functionalized with a nuclear localization signal peptide for cell nucleus imaging. Nanoscale 2015, 7, 6104−6113. (48) Ye, M.; Lu, Z.; Hu, Y.; Zhang, Q.; Yin, Y. Mesoporous titanatebased cation exchanger for efficient removal of metal cations. J. Mater. Chem. A 2013, 1, 5097−5104. (49) Tossell, J. A. Theoretical studies on the formation of mercury complexes in solution and the dissolution and reactions of cinnabar. Am. Mineral. 1999, 84, 877−883. (50) Laoire, C. O.; Mukerjee, S.; Abraham, K. M.; Plichta, E. J.; Hendrickson, M. A. Influence of Nonaqueous Solvents on the Electrochemistry of Oxygen in the Rechargeable Lithium-Air Battery. J. Phys. Chem. C 2010, 114, 9178−9186. (51) Shan, C.; Ma, Z.; Tong, M.; Ni, J. Removal of Hg(II) by poly(1-vinylimidazole)-grafted Fe3O4@SiO2 magnetic nanoparticles. Water Res. 2015, 69, 252−260. (52) Rostamian, R.; Najafi, M.; Rafati, A. A. Synthesis and characterization of thiol-functionalized silica nano hollow sphere as a novel adsorbent for removal of poisonous heavy metal ions from water: Kinetics, isotherms and error analysis. Chem. Eng. J. 2011, 171, 1004−1011. (53) Wang, M.; Qu, R.; Sun, C.; Yin, P.; Chen, H. Dynamic adsorption behavior and mechanism of transition metal ions on silica gels functionalized with hydroxyl- or amino-terminated polyamines. Chem. Eng. J. 2013, 221, 264−274. (54) Qu, R.; Zhang, Y.; Sun, C.; Wang, C.; Ji, C.; Chen, H.; Yin, P. Adsorption of Hg(II) from an Aqueous Solution by Silica-Gel Supported Diethylenetriamine Prepared via Different Routes: Kinetics, Thermodynamics, and Isotherms. J. Chem. Eng. Data 2010, 55, 1496−1504. (55) Wang, L. L.; Luo, F.; Dang, L. L.; Li, J. Q.; Wu, X. L.; Liu, S. J.; Luo, M. B. Ultrafast high-performance extraction of uranium from seawater without pretreatment using an acylamide- and carboxylfunctionalized metal-organic framework. J. Mater. Chem. A 2015, 3, 13724−13730. (56) Li, B.; Zhang, Y.; Ma, D.; Shi, Z.; Ma, S. Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution. Nat. Commun. 2014, 5, 5537. (57) Jiang, S. Y.; He, W. W.; Li, S. L.; Su, Z. M.; Lan, Y. Q. Introduction of Molecular Building Blocks to Improve the Stability of F

DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry Metal-Organic Frameworks for Efficient Mercury Removal. Inorg. Chem. 2018, 57, 6118−6123. (58) Luo, X.; Shen, T.; Ding, L.; Zhong, W.; Luo, J.; Luo, S. Novel thymine-functionalized MIL-101 prepared by post-synthesis and enhanced removal of Hg2+ from water. J. Hazard. Mater. 2016, 306, 313−322. (59) Langmuir, I. The constitution and fundamental properties of solids and liquids. Part I. Solids. J. Am. Chem. Soc. 1916, 38, 2221− 2295.

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DOI: 10.1021/acs.inorgchem.8b03505 Inorg. Chem. XXXX, XXX, XXX−XXX