Herein, a new cationic Cu(
ii
)-based porous and water stable metal-organic framework (MOF), {Cu(bipy)
1.5
(H
2
pdm)}·2NO
3
·H
2
O
n
(
Cu-MOF-1
), is synthesised
via
a slow evaporation process using ...pyridine-2,6-dimethanol (H
2
pdm) and 4,4′-bipyridine (bipy). The MOF is characterized using Fourier-transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), magnetic analysis and single-crystal X-ray diffraction analysis. The structural unit of
Cu-MOF-1
consists of two Cu(
ii
) ions bridged by bipy and supported by H
2
pdm. This material exhibits excellent sensing ability for nitrobenzene (NB) and fluoride ions (F
−
) in 100% aqueous medium with an ultra-low limit of detection of 0.093 and 1.203 ppb for NB and F
−
, respectively. The detection of nitro aromatic compounds (NACs) was found to be governed by photo-induced electron transfer (PET) and fluorescence resonance energy transfer (FRET) mechanisms, while vapour pressure played a major role in NB detection, with a high fluorescence quenching of 96.4%. Moreover, the MOF showed high water stability, significant recyclability and microporosity. The MOF was also employed for the adsorption and separation of methylene blue (MB) from a mixture of three dyes (MB, rhodamine-B and methyl orange). At equilibrium, the removal percentage of
Cu-MOF-1
for MB was 98.23% and the mechanism of dye adsorption was also explored. Thus, the present MOF was determined to be a sustainable multifunctional material for the aqueous phase sensing of hazardous NB and fluoride ions, as well as an excellent dye adsorbent.
A novel metal organic framework (MOF) exhibits good aqueous phase sensing properties towards nitrobenzene and fluoride anions and selective adsorption/separation ability for methylene blue.
A Cu(II) based molecular framework is designed, characterized and explored as superior material for efficient adsorption and separation of aromatic organic pollutant (methylene blue) from water ...bodies through non-covalent interactions.
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•A new cationic Cu(II)-based metal organic framework (Cu-btc-1) is reported.•The Cu-btc-1 is characterized by FTIR, PXRD, TGA, and single crystal X-ray studies.•The present MOF is water stable and shows recyclability.•The material has been employed in adsorption and separation of methylene blue from the mixture dyes.•At equilibrium, removal efficiency of MB by Cu-btc-1 was found to be 98.67%.•The mechanism of adsorption is the result of interplay of the non-covalent contacts.
In view of the increasing demand of the better adsorbents for separation of organic aromatic pollutants from waste water, we have made an attempt to design a stable polymeric material for the purpose. In this report, a copper based metal organic framework (MOF), Cu2(Hbtc)2(H2O)2(µ2-H2O)H2O (Cu-btc-1), where H3btc = benzene-1,2,4-tricarboxylic acid is synthesized employing one pot solvothermal method. The crystalline material, Cu-btc-1 is characterized by single crystal X-ray, XRPD, TGA and various spectroscopic techniques. X-ray data confirm that Cu(II) is present in square pyramidal environment. Topological features reveal the hxl topology of the MOF. The present MOF (Cu-btc-1) is water stable and recyclable and therefore has been employed in adsorption and separation of methylene blue with excellent efficiency from the mixture of three organic dyes, methylene blue (MB), methyl orange (MO) and rhodamine (Rh-B) in aqueous phase. MB was observed to show highest adsorption of nearly 98% at neutral pH and optimum temperature (25 °C). At equilibrium, the removal efficiency of Cu-btc-1 towards MB from the mixture of dyes was found to be 98.67%. The efficiency and highest adsorption of MB could be attributed to the cationic nature of the dye and nucleophilic aromatic moieties of carboxylates of Cu-btc-1 framework where strong electrostatic interactions take place for adoption of the MB+ molecules. Not only the cationic nature but also the linearity of the MB helps enhance its adsorption by the adsorbent by easily approaching to the sites available on MOF. H-bonding and π–π interactions are also responsible for the adsorption of the dye molecules here. Thus, mechanism of adsorption is the result of interplay of the electrostatic attraction/repulsion, π–π interactions, H-bonding and weak Van der Waals interactions. The present MOF thus represents an excellent class of adsorbent material and establishes a fine tuning between the structure-efficiency relationships for separation of the aromatic organic dyes in aqueous medium for future endeavours.
A 2D cobalt(II) metal organic frameworks with bey topology exhibits excellent adsorption and separation of methylene blue (a cationic dye) through cation-π interactions.
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•A two ...dimensional molecular framework, (1,2-DPE)Co2Cl2n (HT-1) is designed.•The topological analysis discloses the bey topology of the network.•The MOF shows rapid and selective adsorption of organic cationic dye.•The dye adsorption is explored in aqueous medium and MOF is reusable.•The interplay of the non-covalent contacts is the key factor behind the adsorption of dye.
Removal of organic pollutants (dyes) by using metal–organic frameworks from the wastewater is emergent hey days owing to the harmful effects of them on environment and water bodies. Herein this work, a 2D metal–organic framework, namely (1,2-DPE)Co2Cl2n (HT-1) has been prepared under solvothermal condition using 1,2-di(4-pyridyl)ethylene (1,2-DPE) as a ligand. The HT-1 is characterized by various analytical, spectral and single crystal X-ray studies. The topological analysis ascertains the bey topology of the MOF with the Co(II) ion present in a tetrahedral environment. We further explored the MOF for its material importance as dye adsorbent using a cationic dye such as methylene blue (MB) as well as an anionic dye such as methyl orange (MO) in aqueous medium. It is concluded that HT-1 has the excellent ability to adsorb cationic dye molecules with excellent efficiency. The highest adsorption of the dye by the MOF was observed at neutral (optimum) pH and room temperature with highest efficiency for removal of MB i.e, 97%. The mechanism behind the better adsorption is cation-π interaction along with other non-covalent contacts existing between the MOF and MB. The presence of any inter-particle diffusion has been ruled out with N2 adsorption isotherm. Moreover, the negligible magnitude of the zeta potential (determined at varying pH) observed at the surface of the MOF suspension also excluded the adsorption phenomenon due to electrostatic interaction between the MOF and the dye. Henceforth, the non-covalent contacts are revealed to be solely responsible for the adsorption process following the pseudo-second order kinetics. Thus, the present MOF comes out as a better model for adsorption and separation of methylene blue in aqueous phase employing non-covalent interactions and this structure–activity tuning of the framework could be used for adsorbing specific dyes in future endeavours.
A new heterometallic cluster system, Cu
3
Gd
2
(H
3
btp)
2
(OAc)
6
·5H
2
O
{Cu
3
-
Gd
2
}
, is designed by employing 1,3-bis(tris(hydroxymethyl)methylamino)propane (H
6
btp) as a ligand. The cluster ...is characterized by FTIR, TGA, PXRD, SCXRD and topological analyses. The crystallography ascertains the presence of two Cu
2+
in square pyramidal and one Cu
2+
in octahedral environments while the two Gd
3+
ions are in a distorted capped square antiprismatic geometry. The ligand is coordinated in an unusual tri-deprotonated form (H
3
btp
3−
). The overall cluster represents a rare example of unique topology 1,2 M3-1. The
M
(
H
) plot recorded at 2 K shows the presence of antiferromagnetic interactions. The cluster exhibits a maximum change in entropy of 15.84 J kg
−1
K
−1
at 3 K for
H
= 7 T thus acting as a new class of magnetic molecular cooler. Furthermore, free -OH groups in the architecture of the cluster facilitate the adsorption of aromatic cationic dye, methylene blue (MB), selectively owing to strong O-H π interactions with good recyclability at ambient pH and temperature. This cluster is a rare example among a few reported discrete units showing structure-property relation for adsorption of MB. The present work opens new doors for designing exotic materials having a tunable magnetocaloric effect (MCE) as well as cationic dye adsorption with notable efficacy and presents the first example of a dual functional material as a coolant and an adsorbent.
A new Cu-Gd system as a dual functional material (as a magnetic refrigerant as well as a cationic dye adsorbent) is designed and explored.
There is an increasing demand for monitoring environmental pollutants and the control requires new sensing materials with better sensitivity, selectivity and reliability. In this study, a series of ...Co
7
clusters incorporating various flexible polyhydroxyamine ligands are explored, with the first report of thiocyanate recognition triggered by crystal formation using a Co
7
crystal (
1
). For this, we have fortunately synthesized three new mixed metal Co
7
clusters with fascinating structural features. The clusters were characterized by spectroscopic and single crystal X-ray diffraction methods and later by DFT calculations. Due to its better emission spectrum,
1
was further utilized for evaluating its sensing ability towards various anions in water. Surprisingly,
1
shows better quenching ability towards the recognition of SCN
−
with a better binding constant. The luminescence quenching towards SCN
−
detection was further verified by the single crystal method, HSAB principle (symbiosis) and theoretical calculations such as DFT studies. The SCXRD data clearly suggest that the Co
7
(
1
) can be converted into Co
14
(
1a
) by direct reaction with NaSCN under ambient conditions. Besides the soft/hard acid-base concept (symbiosis), the energies of formation, and Co-NCS and Co-OH
2
bond energies (as unravelled by DFT) are responsible for this transformation. Therefore,
1
can be used as a selective and sensitive sensor for the detection of thiocyanate anions based on the fluorescence amplification and quenching method. Further, the designed cluster has also been utilized to detect anions in human blood samples to differentiate a smoker and a non-smoker. It has been concluded that the samples of smokers have a high degree of thiocyanate (∼12 or 9.5 mg L
−1
) in comparison to those of non-smokers (2-3 mg L
−1
). Thus, this kind of cluster material has high potentiality in the field of bio-medical science in future endeavours for identification of the extent of thiocyanate content in smokers.
A new Co based sensor for thiocyanate recognition by formation of the dimeric crystals is designed to distinguish a smoker from a non-smoker.
In view of the fascinating applications of hybrid materials, a new nanocomposite is fabricated in order to achieve the excellent adsorption capacity for cationic dye as well as selective sensing ...ability toward Cr6+ ions in the aqueous phase. The present work deals with the synthesis of metal-organic framework (MOF) based nanocomposite, i.e., Co-MOF@CNT using Co-MOF and functionalized carbon nanotubes (CNTs) by adopting a facile, in-situ solvothermal approach for application in the field of wastewater treatment. The as-synthesized nanocomposite was characterized in detail through Fourier transform infrared spectroscopy (FTIR), Raman, powder X-ray diffraction (PXRD), thermal gravimetric analysis/differential thermal analysis (TGA/DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques, revealing the successful fabrication of both parent materials in the hybrid nanocomposite. The developed nanocomposite (Co-MOF@CNT) was assessed for its application in metal sensing as well as for the selective adsorption and elimination of hazardous cationic dyes from the mixture containing cationic dye, methylene blue (MB) and anionic dye, methyl orange (MO) from wastewater. The nanocomposite exhibits high selectivity and metal-sensing response towards Cr6+ ion under ambient conditions with an ultra-low detection limit of ∼0.00649 ppm or 0.125 μM, as reported so far. Moreover, the detection ability of Co-MOF@CNT can be restored for up to five cycles significantly. In addition, the developed nanocomposite displayed a high removal rate of about 98% at equilibrium under optimum temperature (25 °C) and neutral pH for cationic (MB) dye with ultimate selectivity. The kinetic studies revealed that the adsorption proceeds via pseudo-second order reaction. The dye adsorption mechanism suggests the presence of electrostatic, ᴫ-ᴫ and hydrogen bonding interactions between nanocomposite and the dye. This hybrid nanocomposite also exhibited high reusability of up to four cycles for MB dye. All in all, Co-MOF@CNT nanocomposite with superior Cr6+ metal sensing performance and MB dye adsorption could pave a promising path for environmental applications in this high-tech industrial era.
A new nano-composite, Co-MOF@CNT has been synthesized, characterized and applied for cationic dye adsorption and Cr(VI) sensing in aqueous environment. Display omitted
•Synthesis of Co-MOF@CNT nanocomposite for wastewater remediation by adopting a simple, in-situ, solvothermal approach is performed.•Composite exhibits excellent metal ion sensing towards Cr6+ with LOD of ∼0.125 μM.•The material can also be employed for effective adsorption of dyes, MB (98%) and MO (72%).•The adsorption follows pseudo-second order kinetic model and shows excellent recyclability for up to four cycles.
The study examined how adding phytase to nonphytate phosphorus (NPP) diets affected performance, egg quality, reproductive hormones, and plasma biochemical indices in 73- to 80-wk-old laying hens. ...Six treatments with 5 replicates of 18 Hy-Line brown laying hens each were randomly assigned. Three isonitrogenous, isocaloric diets containing consistent calcium levels (3.8%) were formulated to contain 0.20, 0.25, and 0.30% NPP, treated with or without phytase supplementation (1,000 FYT per kg feed, Ronozyme HiPhos-L, Aspergillus oryzae 6-phytase). The results showed that the addition of phytase to the diet containing 0.20, 0.25, and 0.30% NPP increased egg production by 1.50, 1.64, and 0.97%, respectively, and improved eggshell thickness. Also, use of phytase in the diet contain 0.25, and 0.30% NPP increased the plasma concentration of albumin (ALB), high-density lipoprotein (HDL), phosphorus (P), and plasma follicle‐stimulating hormone (FSH), plasma calcium (Ca), estradiol‐17β (E2β), and luteinizing hormone (LH). In contrast, the egg weight, feed intake, egg mass, feed conversion ratio, albumen height, Haugh unit, yolk, and shell color were unaffected. It can be advisable to use phytase supplementation in an elderly laying hen's diet contain 0.25, and 0.30% NPP to improve shell quality and positively impact reproductive hormones leading to the persistence of egg production.
For environmental protection, the effectual capture of radioiodine produced or released as nuclear fission products, is of utmost importance. In this aspect, metal-organic frameworks (MOFs) may be a ...kind of promising material to address this hazardous environmental issue. Herein, four different MOFs, Co1.5(PhCOO)3(bpy)0.5n (KQ-1), Co(HCOO)2(bpy)n (KQ-2), Co(HCOO)2n (KQ-3) and Mn(HCOO)2n (KQ-4) have been synthesized via solvothermal method by using benzoic acid (PhCOOH) or formic acid (HCOOH) as organic linker, 4,4′-bipyridine (bpy) as spacer and salts of Co(II) and Mn(II). The as-prepared MOFs were characterized in detail and their iodine (I2) adsorption/release performance was also investigated in vapor and solution phase by UV-Vis spectroscopy with the adsorption capacity being KQ-1 >KQ-2 >KQ-3 ≈ KQ-4. The highest sorption capacity of about 551 and 131.05 mg/g was observed for KQ-1 in vapor and solution phase, respectively, and with recyclability upto five cycles. Raman and XPS spectra indicate that iodine binds to MOF as I2 and I3- species. The plenty of aromatic rings form iodine-π charge transfer complex thus stabilizing the interaction to effect the iodine sorption (as evidenced in KQ-1). Henceforth, the iodine sorption is observed to depend on the presence of aromatic rings in the structure of MOFs.
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The iodine capture by four MOFs with remarkable capacity has been analyzed in solid and liquid phases which reveals that the sorption is due to the presence of π rings in the MOFs.
•Four new MOFs are synthesized and characterized.•Iodine (I2) adsorption by the MOFs has been assessed in vapour and liquid phases.•The highest sorption capacity 551 (vapour) and 131.05 (liquid) mg/g was observed for MOF, KQ-1.•Iodine binds to MOF as I2 and I3- species.•The structure-iodine capture relationship has been well established.
Herein, metal–organic framework (MOF)-based adsorbents are designed with distinct hard and soft metal building units, namely, Co2 ICoII(PD)2(BP) (Co_PD-BP) and Cu2 ICuII(PD)2(BP) (Cu_PD-BP), where ...H2PD = pyrazine-1,4-diide-2,3-dicarboxylic acid and BP = 4,4′-bipyridine. The designed MOFs were characterized via spectral and SCXRD techniques, which confirm the mixed-valent states (+1 and +2) of the metal ions. Topological analysis revealed the rare ths and gwg topologies for Co MOF, while Cu-MOF exhibits a unique 8T21 topology in the 8-c net (point symbol for net: {424·64}). Moreover, severe environmental issues can be resolved by effectively removing heterocyclic organosulfur compounds from fuels via adsorptive desulfurization. Further, the developed MOFs were investigated for sulfur removal via adsorptive desulfurization from a model fuel consisting of dibenzothiophene (DBT), benzothiophene (BT), and thiophene (T) in the liquid phase using n-octane as a solvent. The findings revealed that Cu_PD-BP effectively removes the DBT with a removal efficiency of 86% at 300 ppm and an operating temperature of 25 °C, with a recyclability of up to four cycles. The adsorption kinetic analysis showed that the pseudo-first-order model could fit better with the experimental data indicating the physisorption process. Further, the studies revealed that adsorption capacity increased with the increasing initial DBT concentration with a remarkable capacity of 70.5 mg/g, and the adsorption process was well described by the Langmuir isotherm. The plausible reason behind the enhanced removal efficiency shown by Cu_PD-BP as compared to Co_PD-BP could be the soft–soft interactions between soft sulfur and soft Cu metal centers. Interestingly, density functional theory (DFT) studies were done in order to predict the mechanism of binding of thiophenic compounds with Cu_PD-BP, which further ascertained that along with other interactions, the S···π and S···Cu interactions predominate, resulting in a high uptake of DBT as compared to others. In essence, Cu_PD-BP turns out to be a promising adsorbent in the field of fuel desulfurization for the benefit of mankind.
Herein, metal-organic framework (MOF)-based adsorbents are designed with distinct hard and soft metal building units, namely, Co
Co
(PD)
(BP) (
) and Cu
Cu
(PD)
(BP) (
), where H
PD = ...pyrazine-1,4-diide-2,3-dicarboxylic acid and BP = 4,4'-bipyridine. The designed MOFs were characterized via spectral and SCXRD techniques, which confirm the mixed-valent states (+1 and +2) of the metal ions. Topological analysis revealed the rare
and
topologies for Co MOF, while Cu-MOF exhibits a unique
topology in the 8-c net (point symbol for net: {4
·6
}). Moreover, severe environmental issues can be resolved by effectively removing heterocyclic organosulfur compounds from fuels via adsorptive desulfurization. Further, the developed MOFs were investigated for sulfur removal via adsorptive desulfurization from a model fuel consisting of dibenzothiophene (DBT), benzothiophene (BT), and thiophene (T) in the liquid phase using
-octane as a solvent. The findings revealed that
effectively removes the DBT with a removal efficiency of 86% at 300 ppm and an operating temperature of 25 °C, with a recyclability of up to four cycles. The adsorption kinetic analysis showed that the pseudo-first-order model could fit better with the experimental data indicating the physisorption process. Further, the studies revealed that adsorption capacity increased with the increasing initial DBT concentration with a remarkable capacity of 70.5 mg/g, and the adsorption process was well described by the Langmuir isotherm. The plausible reason behind the enhanced removal efficiency shown by
as compared to
could be the soft-soft interactions between soft sulfur and soft Cu metal centers. Interestingly, density functional theory (DFT) studies were done in order to predict the mechanism of binding of thiophenic compounds with
, which further ascertained that along with other interactions, the S···π and S···Cu interactions predominate, resulting in a high uptake of DBT as compared to others. In essence,
turns out to be a promising adsorbent in the field of fuel desulfurization for the benefit of mankind.
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