Cu-BTC Metal Organic Framework Research Articles

CuBTC metal organic framework-based dispersive solid phase extraction of cyclosporine and tacrolimus from plasma samples prior to determination by high performance liquid chromatography-tandem mass spectrometry

Immunosuppressive drugs are prescribed to reduce the immune system of persons who are undergoing organ transplants. The concentration of these drugs in blood and plasma samples must be accurately and precisely determined during immunosuppressive therapy due to their significant side effects. In this study, a metal organic framework-based dispersive solid phase extraction method was developed for the extraction of tacrolimus and cyclosporine from plasma samples before their determination by high performance liquid chromatography-tandem mass spectrometry. For this purpose, CuBTC metal organic framework nanoparticles were prepared by a hydrothermal approach and they were used as the sorbent in the extraction procedure. The adsorbed analytes were eluted by a suitable organic solvent and then more concentrated by evaporation of the eluate. All of the effective parameters of the method including sorbent amount, adsorption time, eluent type, desorption time, eluent volume, and sample solution pH were studied and optimized. They were obtained 5 mg, 5 min, acetone, 5 min, 300 μL, and 5, respectively. Under optimal conditions, the developed method was validated and the data showed that the linear range, the limit of detection, the limit of quantification, the coefficient of determination, the enrichment factor, and relative standard deviation values were 1–1000 ng mL−1, 0.30 ng mL−1, 0.5 ng mL−1, 0.99, 15.6, and 5.8 % for tacrolimus and 0.8–500 ng mL−1, 0.25 ng mL−1, 0.4 ng mL−1, 0.99, 17, and 5.6 % for cyclosporine, respectively. Finally, the method was successfully used in the determination of the studied drugs in plasma samples.

Epitaxial Single-Domain Cu-BTC Metal-Organic Framework Thin Films and Foils by Electrochemical Conversion of Cuprous Oxide.

Metal-organic frameworks (MOFs) are an important class of crystalline porous materials with extensive chemical and structural merits. However, the fabrication of MOF thin films oriented along all crystallographic axes to achieve well-aligned nanopores and nanochannels with uniform apertures remains a challenge. Here, we achieved highly crystalline single-domain MOF thin films with the [111] out-of-plane orientation by electrochemical conversion of cuprous oxide. Copper(II)-benzene-1,3,5-tricarboxylate, Cu3(BTC)2 (referred to as Cu-BTC), is a well-known metal-organic open framework material with a cubic crystal system. Epitaxial Cu-BTC(111) thin films were manufactured by electrochemical oxidation of Cu2O(111) films electrodeposited on single-crystal Au(111). The Cu-BTC(111) shows an in-plane antiparallel relationship with the precursor Cu2O(111) with a -0.91% coincidence site lattice mismatch. A plausible mechanism was proposed for the electrochemical conversion of Cu2O into Cu-BTC, indicating formation of intermediate CuO, growth of Cu-BTC islands, and termination with coalesce into a dense film with a limiting thickness of about 740 nm. The Faradaic efficiency for the electrochemical conversion was 63%. In addition, epitaxial Cu-BTC(111) foils were fabricated by epitaxial lift-off following the electrochemical etching of residual Cu2O underneath the Cu-BTC. It was also demonstrated that Cu-BTC(111) films with two in-plane domains and textured Cu-BTC(111) films can be achieved on a large scale using electrodeposited Au/Si and Au-coated glass as low-cost substrates.

Ru doping induced lattice distortion of Cu nanoparticles for boosting electrochemical nonenzymatic hydrogen peroxide sensing

In this paper, we report a new strategy to activate the electrocatalytic activity of Cu to realize the non-enzymatic detection of hydrogen peroxide. The Ru-doped copper nanoparticles were prepared on the surface of carbon materials by direct pyrolysis of Ru in exchange for Cu-BTC metal-organic framework. The materials were characterized by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD). Surprisingly, Ru doping induced obvious lattice distortion of Cu nanoparticles, which made Cu nanoparticles exhibit excellent electrocatalytic activity for hydrogen peroxide reduction. The sensor based on Ru-doped Cu nanoparticles can detect hydrogen peroxide in a wide linear range from 0.01 mM to 5.55 mM. Moreover, as a hydrogen peroxide sensor, it has a high sensitivity of 327.14 µA·mM−1·cm−2 and a low detection limit of 8.9 µM. Therefore, Cu nanoparticles with the lattice distortion was demonstrated to be a potential material for hydrogen peroxide electrochemical sensor.

DDTC-Cu(I) based metal-organic framework (MOF) for targeted melanoma therapy by inducing SLC7A11/GPX4-mediated ferroptosis

Disulfiram (DSF), a drug for alcohol withdrawal, has attracted extensive scientific attention due to its potential to treat cancer. The metabolite of DSF, diethyl dithiocarbamate (DDTC), forms a Cu-DDTC complex in vivo with copper ions, which has been shown to be a proteasome inhibitor with high antitumor activity. However, the in vivo stability of Cu-DDTC complexes remains a challenge. In this study, the nanomedicine Cu-BTC@DDTC with high antitumor activity was prepared by using the nanoscale metal-organic framework (MOF) Cu-BTC as a carrier and loading diethyldithiocarbamate (DDTC) through coordination interaction. The results showed that Cu-BTC@DDTC had high drug loading and adequate stability, and exhibited DDTC-Cu(I) chemical valence characteristics and polycrystalline structure features. In vitro cytocompatibility investigation and animal xenograft tumor model evaluation demonstrated the anti-cancer potential of Cu-BTC@DDTC, especially the combination of Cu-BTC@DDTC with low-dose cisplatin showed significant antitumor effect and biosafety. This study provides a feasible protocol for developing antitumor drugs based on the drug repurposing strategy.

Concentration and LBL cycle evolution to the Cu-BTC metal organic framework: Optimization as functional layer to the solar cell devices

Metal-organic frameworks are rational self-assembly of metal-ions and organic-linkers, and are class of hybrid porous materials those endowed with unique physiochemical properties. To seek cost effective renewable energy resources, solar cell technology has potential to cater futuristic energy need of society, where MOFs may play an important role to develop cost effective and eco-friendly devices. Therefore, in this work, properties of Copper-based MOFs are investigated in aspect to functional layer applications to solar cell devices where synthesis of Cu3(BTC)2 MOFs is accomplished by establishing coordination between Copper (II) ions and 1,3,5 benzene tricarboxylic acid (BTC) linker using solvothermal method. Developed Cu3(BTC)2 MOFs are subjected to various characterization tools where, structural analysis revealed dominance of (222) reflection and successful formation of Copper-based frameworks. Thermogravimetric analysis indicated first and second weight losses corresponding to temperature ranges of 114–130 °C and 360–375 °C, respectively. FTIR analysis exposed presence of symmetric and asymmetric modes of carboxylic groups and CH bending mode. Surface morphological analysis revealed to the formation of pyramidal coordination geometry of Copper-based frameworks whereas compositional analysis confirmed successful synthesis of Cu3(BTC)2 frameworks. The solar cell devices having architecture as Glass/FTO/TiO2/Cu-BTC/CuSCN/Ag are fabricated with 5, 10, and 15 LBL cycles of Cu-BTC MOFs. The device with 10 LBL cycles exhibited better performance vis-à-vis the others. The attained results signify that synthesized bulk Cu-BTC MOF material and device fabricated with 10 LBL cycles draw attention to further undertake materials evolution for development of high performance solar cell devices.

Electrospinning synthesis of CuBTC/TiO2/PS composite nanofiber on HEPA filter with self-cleaning property for indoor air purification

In this study, we have developed a cure for indoor air pollution. Herein, we have fabricated CuBTC metal-organic framework MOF combined with TiO2 nanoparticle hybrid material by solvothermal method and obtained it in powder form. The CuBTC/TiO2 hybrid material absorbed toluene higher than TiO2 and CuBTC. CuBTC/TiO2 powder hinders its practical application, however, for the first time, CuBTC/TiO2/PS-based nanofibers were electrospun on a commercial HEPA filter using the electrospinning process in order to examine their air-filtering capabilities. This air filter exhibited 98.6% adsorption efficiency and 129.45 mg g-1 toluene gas adsorption capacity, although pristine HEPA was incapable of absorbing toluene. After the saturated point, a self-cleaning strategy was employed under UV light for regeneration purposes. In addition, the CuBTC/TiO2/PS nanofiber demonstrated superior PM2.5 removal performance, with a 99.82% filtration rate. Compared to a pure HEPA filter, the CuBTC/TiO2/PS-C nanofiber-based HEPA filter has a very high filtration rate and negligible pressure drop when evaluated at various airflow velocities. This study gives significant insight into the design of a self-cleaning nanofiber air filter to protect public health from indoor air pollution and save lives in the near future.

Exploitation of multi-walled carbon nanotubes/Cu(ii)-metal organic framework based glassy carbon electrode for the determination of orphenadrine citrate.

Metal organic frameworks (MOFs), with structural tunability, high metal content and large surface area have recently attracted the attention of researchers in the field of electrochemistry. In this work, an unprecedented use of multi-walled carbon nanotubes (MWCNTs)/copper-based metal-organic framework (Cu-BTC MOF) composite as an ion-to-electron transducer in a potentiometric sensor is proposed for the determination of orphenadrine citrate. A comparative study was conducted between three proposed glassy carbon electrodes, Cu-MOF, (MWCNTs) and MWCNTs/Cu-MOF composite based sensors, where Cu-MOF, MWCNTs and their composite were utilized as the ion-to-electron transducers. The sensors were developed for accurate and precise determination of orphenadrine citrate in pharmaceutical dosage form, spiked real human plasma and artificial cerebrospinal fluid (ACSF). The sensors employed β-cyclodextrin as a recognition element with the aid of potassium tetrakis(4-chlorophenyl)borate (KTpCIPB) as a lipophilic ion exchanger. The sensors that were assessed based on the guidelines recommended by IUPAC and demonstrated a linear response within the concentration range of 10-7 M to 10-3 M, 10-6 M to 10-2 M and 10-8 M to 10-2 M for Cu-MOF, MWCNTs and MWCNTs/Cu-MOF composite based sensors, respectively. MWCNTs/Cu-MOF composite based sensor showed superior performance over other sensors regarding lower limit of detection (LOD), wider linearity range and faster response. The sensors demonstrated their potential as effective options for the analysis of orphenadrine citrate in quality control laboratories and in different healthcare activities.

Significantly boosted activity for styrene oxidation through simultaneous regulation of porosity and copper sites in microporous metal–organic framework Cu-BTC

Herein, a series of novel HP-DEMOFs were prepared and employed as catalysts for the heterogeneous styrene oxidation reaction. They exhibited much higher conversion than that of the microporous Cu-BTC structure under the same reaction conditions.

Boosting vegetation, biochemical constituents, grain yield and anti-cancer performance of cultivated oat (Avena sativa L) in calcareous soil using oat extracts coated inside nanocarriers

Calcareous soil contains many problems such as the lack of sources of major and minor elements that are useful for plant growth and development. Plant extracts and nanoparticles are very popular as biostimulants in plant production. Here, the effect of aqueous, non-aqueous and alcoholic oat extracts on the growth, biochemical response of oats leaves and grains grown in experimental fields under new reclamation lands were studied. Moreover, different oat extracts were a pathway through the copper-dependent metal–organic framework (MOFs) to separate bioactive molecules from extracts such as salicylic acid, anthraquinone, and triacylglycerol. Additionally, the separated molecules incorporated in Cu-BTC MOFs and oats extracts missed active molecules were spray applied on oat plants. The results showed that the treated plants showed stimulatory responses in growth and physiology. The treatments improved plant growth and biomass, enhanced total protein, water-soluble carbohydrates, free phenolic compounds content in oat leaves, photosynthesis, and chlorophyll contents. The treatments also improved the level of vitamins E and K, phenolic compounds, and avenanthramides C in the oat grains. Moreover, the treatments showed an improvement in the yield of oats (grain and straw) using water and alcoholic oat extracts in which the active molecules were missed. Our findings demonstrate that Cu-BTC and oats extracts can act as a biostimulant to enhance the biological and chemical properties of oats and increase the yield in calcareous soils. The cytotoxicity study of oats (produced from AE, c@Cu-BTC, and AE-c treatments) was conducted using Vero Cell lines. The anticancer activities of different oat grains were carried out using MCF 7cell lines. The results show that the grains produced from the AE, c@Cu-BTC, and AE-c treatments possessed 94.3, 72.3, and 100% activity towards the cancer cell line. Removal of growth inhibitors from spray solutions increases grain yield and anticancer activity.

Immobilization of Lipase in Cu-BTC MOF with Enhanced Catalytic Performance for Resolution of N-hydroxymethyl Vince Lactam.

Metal-organic frameworks (MOFs) can be used as the immobilization carriers to protect the physicochemical properties of enzymes and improve their catalytic performance. Herein, we report an in situ co-precipitation method to immobilize lipase from Candida sp. 99-125 in Cu-BTC MOF (BTC = 1, 3, 5-benzene tricarboxylic acid, H3BTC). Characterizations of the immobilized lipase (lipase@Cu-BTC) have confirmed the entrapment of lipase molecules in Cu-BTC MOF. The immobilized lipase has been successfully applied for resolving N-hydroxymethyl vince lactam (N-HMVL) and its catalytic activity is five times that of native enzyme. More importantly, we found that Cu-BTC MOF can afford powerful protection for enzyme in nearly dry organic solvent and endow the immobilized lipase with excellent reusability and storage stability. Our present study may widen the application of immobilized enzyme with MOF as the immobilized carrier.

Polydopamine imprinted polymer-based tunable electrochemical synthesis of copper benzene-1, 3, 5-tricarboxylate metal-organic framework film as a hybrid dual recognition element for ultra-trace sensing of pregabalin (lyrica)

The present study propounds an innovative diagnostic hybrid dual recognition strategy to detect trace amounts of pregabalin (PGB) using the combination of two powerful metal-organic framework (MOF) structures and the molecularly imprinted polymer (MIP) technique. To improve the analytical property of the electrode surface, copper-benzene-1,3,5-tricarboxylic acid frameworks (Cu-BTC MOFs) were directly synthesized on the glassy carbon electrode (GCE). Afterwards, MIP film was synthesized via the in situ dopamine (DA) electropolymerization method. To explore the effect of independent variables on the MIP construction, the Box-Behnken design was considered to determine the response surface methodology. In this sense, the predicted optimum combination variables were DA= 3 mM, pH = 7.4, cycle number = 16, KOH 4 mM, KOH: Et-OH ratio of 5:1 and 18 min elution time. Incubation time was obtained at 12 min. Electrochemical impedance spectroscopy (EIS) was used to determine the PGB analyte. The linear dynamic concentration range and limit of detection (LOD) were 0.05–800 pM and 2.9 fM, respectively. The imprinting calculated factor was 24.60, showing high interaction between the PGB and DA monomer. Inter-day and intra-day reproducibility measurements showed 2.08% and 1.58% and, 98% of the initial current response was maintained. Coefficients of selectivity against the PGB, for tapentadol, gabapentin, levetiracetam, L -Carnitine, and L -Histidine were 1, 5.52, 8.75, 2.8, 6.56 and 6.56 respectively. Cyclic voltammetry (CV) at various scan rates verified that adsorption kinetics follows a diffusion control mechanism. Finally, the efficiency of the GCE/Cu-BTC/ePDA-MIP sensor in real samples was evaluated and satisfactory results were achieved. • Combining two powerful molecularly imprinted polymer and metal-organic framework methods. • Direct growth of copper-organic framework mediated by copper hydroxide nano-strips. • In situ dopamine potentiodynamic electropolymerization. • Optimize electropolymerization conditions with Box-Behnken method. • Ultra-trace detection of pregabalin by prepared sensor.

Strategy to improve Cu-BTC metal-organic frameworks performance in removal of Rhodamine B: MD and WT-MtD simulations assessment

With industry progress, environmental problems have begun to threaten human health. Among them, water pollution is closely related to human life and has attracted researchers’ attention. Hence, coping strategies for these pollutants have become a priority nowadays. Here, we carried out the molecular dynamics (MD) and well-tempered metadynamics simulations to evaluate the interaction of Rhodamine B (Rh B) with a copper (II)-benzene-1,3,5-tricarboxylate metal-organic framework (Cu-BTC/MOF). To design a more efficient dye removal platform, the effect of the -NH2, -OH, and -NO2 functional groups on the efficiency of Cu-BTC/MOF in the adsorption of Rh B is investigated. It is found that the interaction energy of Rh B with -NH2-MOF, -OH-MOF, and -NO2-MOF is about −79.98, −121.87, and −365.55 kJ mol−1, respectively, more than the pristine case. This observation confirms that the functionalization strategy can enhance the Cu-BTC/MOF efficiency. The obtained free energy (FE) values from the metadynamics simulation indicated that for adsorption of Rh B on pristine, -NH2-MOF, -OH-MOF, and -NO2-MOF, the global minimums are located about at −220.47, −234.75, −236.09, and −259.01 kJ mol−1, respectively. The obtained results show that in the two-dimensional FE surfaces, the most stable complex with Rh B belongs to the MOF-NO2 system.

Hydrogen production employing Cu/Zn-BTC metal-organic framework on cordierite honeycomb ceramic support in methanol steam reforming process within a microreactor

Three metal-organic frameworks Cu-BTC, Zn-BTC, and Cu/Zn-BTC were prepared and impregnated in nitrate solutions to obtain the precursors. After calcination, three metal-BTC-derived CuO/ZnO/CeO2/ZrO2 catalysts were obtained. The samples were characterized and the catalyst-coated cordierite honeycomb ceramics were used in a microreactor for methanol steam reforming at different reaction conditions. Results showed that the Cu/Zn-BTC-derived catalyst exhibited the most fine and uniform particles, the best reducibility, the largest specific surface area, and the optimal surface elemental state due to the difference in the formation mechanisms, resulting in its remarkable catalytic performance. The ceramic support coated with Cu/Zn-BTC-derived catalyst could achieve 100% methanol conversion rate and 0.336 mol/h H2 output at 260 °C in the microreactor. Stability tests demonstrated that the Cu/Zn-BTC-derived catalyst could maintain its excellent performance without deactivation within 30 h continuous reaction, which was connected with the Ce–Zr–O solid solution with high concentration of oxygen vacancies and surface oxygen.

Improved antibacterial activity by incorporation of silver sulfadiazine on Nanoporous Cu-BTC Metal-organic-framework

Silver sulfadiazine (SSD) as an antibacterial agent is widely used in the topical treatment of wound infections. Metal-organic frameworks (MOFs) have also been considered in the field of drug delivery in recent years due to their attractive properties. In this work, in order to increase the antibacterial efficiency, the Cu-BTC MOF was used as a platform for the incorporation of SSD. Physical characterization of compounds was performed using FT-IR, PXRD, SEM, TEM, EDX-mapping, N2 adsorption-desorption, TGA and ICP-OES techniques. The performance of the compounds against Staphylococcus aureus and Escherichia coli bacterium was assessed by agar well diffusion and plate colony count bioassays. The results showed that in both methods, the effectiveness of SSD@Cu-BTC is more than Cu-BTC and SSD. The gradual release of silver and copper and their synergistic effect was the reason for improving and a time-dependent antibacterial activity in SSD@Cu-BTC.

Survey on Adsorption of Low Molecular Weight Compounds in Cu-BTC Metal-Organic Framework: Experimental Results and Thermodynamic Modeling.

This contribution aims at providing a critical overview of experimental results for the sorption of low molecular weight compounds in the Cu-BTC Metal–Organic Framework (MOF) and of their interpretation using available and new, specifically developed, theoretical approaches. First, a literature review of experimental results for the sorption of gases and vapors is presented, with particular focus on the results obtained from vibrational spectroscopy techniques. Then, an overview of theoretical models available in the literature is presented starting from semiempirical theoretical approaches suitable to interpret the adsorption thermodynamics of gases and vapors in Cu-BTC. A more detailed description is provided of a recently proposed Lattice Fluid approach, the Rigid Adsorbent Lattice Fluid (RALF) model. In addition, to deal with the cases where specific self- and cross-interactions (e.g., H-bonding, Lewis acid/Lewis base interactions) play a role, a modification of the RALF model, i.e., the RALFHB model, is introduced here for the first time. An extension of both RALF and RALFHB is also presented to cope with the cases in which the heterogeneity of the rigid adsorbent displaying a different kind of adsorbent cages is of relevance, as it occurs for the adsorption of some low molecular weight substances in Cu-BTC MOF.

Controllable Nitric Oxide Storage and Release in Cu-BTC: Crystallographic Insights and Bioactivity.

Crystalline metal–organic frameworks (MOFs) are extensively used in areas such as gas storage and small-molecule drug delivery. Although Cu-BTC (1, MOF-199, BTC: benzene-1,3,5-tricarboxylate) has versatile applications, its NO storage and release characteristics are not amenable to therapeutic usage. In this work, micro-sized Cu-BTC was prepared solvothermally and then processed by ball-milling to prepare nano-sized Cu-BTC (2). The NO storage and release properties of the micro- and nano-sized Cu-BTC MOFs were morphology dependent. Control of the hydration degree and morphology of the NO delivery vehicle improved the NO release characteristics significantly. In particular, the nano-sized NO-loaded Cu-BTC (NO⊂nano-Cu-BTC, 4) released NO at 1.81 µmol·mg−1 in 1.2 h in PBS, which meets the requirements for clinical usage. The solid-state structural formula of NO⊂Cu-BTC was successfully determined to be [CuC6H2O5]·(NO)0.167 through single-crystal X-ray diffraction, suggesting no structural changes in Cu-BTC upon the intercalation of 0.167 equivalents of NO within the pores of Cu-BTC after NO loading. The structure of Cu-BTC was also stably maintained after NO release. NO⊂Cu-BTC exhibited significant antibacterial activity against six bacterial strains, including Gram-negative and positive bacteria. NO⊂Cu-BTC could be utilized as a hybrid NO donor to explore the synergistic effects of the known antibacterial properties of Cu-BTC.

Fast Charge Transfer and High Stability via Hybridization of Hygroscopic Cu-BTC Metal-Organic Framework Nanocrystals with a Light-Absorbing Layer for Perovskite Solar Cells.

Perovskite solar cells (PSCs) have great potential as an efficient solar energy harvesting system due to their outstanding optoelectronic properties, but the charge accumulation and recombination, as well as the moisture-induced degradation of the light-absorbing perovskite layers, remain great bottlenecks in practical applications for future technology. As a solution to this challenge, here we report a strategy to realize moisture-stable PSCs allowing fast charge transfer that, in turn, leads to high power conversion efficiency (PCE). Hybridization of hygroscopic copper(II) benzene-1,3,5-tricarboxylate metal-organic frameworks (Cu-BTC MOFs) with a light-absorbing perovskite layer for PSCs, where a moderate level of moisture attracted by Cu-BTC MOFs during the synthesis step, leads to enhanced perovskite crystallization. Besides, the perovskite-MOF hybrid facilitates the transfer of photoexcited electrons from the perovskite to TiO2 by providing additional channels for electron extraction. This enables a high PCE of 20.5% in a triple-cation perovskite-MOF device with negligible hysteresis compared to reference devices. Moreover, the perovskite-MOF hybrid exhibits high stability in ambient air under dark conditions over a long period (up to 22 months), while the unmodified counterpart quickly decomposes into PbI2. Consequently, this work provides a promising clue to realizeing fast charge transfer and high stability for high-performance PSCs.

Enhanced Methylene Blue Adsorption by Cu-BTC Metal-Organic Frameworks with Engineered Particle Size Using Surfactant Modulators

Metal–organic frameworks (MOFs) featuring porous structures and large specific surface areas have shown great potential in removing organic pollutants from wastewater via adsorption processes. Although the particle size of MOFs determines the adsorption performance (something known as the size-dependent effect), engineering it into desirable dimensions for enhancing the adsorption performance is a great challenge. Here, we develop a practical and facile approach to regulate the particle size of copper benzene-1,3,5-tricarboxylate (Cu-BTC) adsorbents with high tunability by screening the functional modulator of various surfactants adding in hydrothermal synthesis procedure. The effect of surfactant type and concentration on the particle size of Cu-BTC was systematically investigated. The results show that the nonionic surfactant polyvinylpyrrolidone (PVP) demonstrated the greatest ability to control the particle size of Cu-BTC among other counterparts (e.g., N, N, N-trimethyl-1-dodecanaminium bromide (DTAB), polyethylene glycol (PEG1000), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS) and hexadecyl trimethyl ammonium bromide (CTAB)). By increasing the PVP concentration to 0.14 mmol L−1, the average particle size of Cu-BTC could be correspondingly reduced by more than ten times, reaching to a comparative smaller value of 2.4 μm as compared with the reported counterparts. In addition, the PVP allowed a large increase of the surface area of Cu-BTC according to porosity analysis, resulting in a great enhancement of methylene blue (MB) adsorption. The PVP-modulated Cu-BTC showed fast adsorption kinetics for MB removal accompanied with a maximum adsorption capacity of 169.2 mg g−1, which was considerably competitive with most of the analogs reported. Therefore, our study may inspire concepts for engineering the particle size of Cu-BTCs with improved properties for more practical applications.

Metal-organic framework on porous TiO2 thin film-coated alumina beads for fractional distillation of plant essential oils.

Fractionation of essential oils is technically challenging due to enormous scaffold diversities and structural complexities as well as difficulties in the implementation of the fractionation in the gas phase. Packing beads with multi-dimensional hierarchical nanostructures have been developed herein to pack fractional columns for atmospheric distillations. Activated alumina beads were coated with a porous TiO2 thin film. Growth of Cu-BTC (benzene-1,3,5-tricarboxylate) crystals in resultant porous surfaces leads to the generation of new nanopores and increased metal centers for differential coordination with diverse components of essential oils. The TiO2 thin film is not only an integral part of the composites but also induces the oriented growth of Cu-BTC metal organic framework (MOF) crystals through coordinative interactions. These Al2O3@TiO2@Cu-BTC MOF beads show very strong absorptive capability for major components of essential oils, except for a single cyclic ether eucalyptol with steric hindrances. The eucalyptol was fractionated by using the column packed with those modified alumina beads from raw materials of Artemisia argyi, and Rosmarinus officinalis with high purities up to 96% and 93%, respectively.

Role of Bimetallic Solutions in the Growth and Functionality of Cu-BTC Metal-Organic Framework.

Bimetallic solutions play a vital role in the growth and functionality of copper trimesate (Cu-BTC) metal–organic frameworks (MOFs). The effect of Ag+, Ca2+, Mn2+, Co2+, and Zn2+ on the growth of Cu-BTC was studied by fabricating M-Cu-BTC MOFs at room temperature using bimetallic M-Cu solutions. While Ag+ in the MOF had a rod-like morphology and surface properties, divalent cations deteriorated it. Moreover, unconventional Cu+ presence in the MOF formed a new building unit, which was confirmed in all the MOFs. Apart from Ag and Mn, no other MOF showed any presence of secondary cations in the structure. While Ag-Cu-BTC showed an improved H2S uptake capacity, other M-Cu-BTC MOFs had superior organic pollutant adsorption behavior. Thus, we have demonstrated that the physicochemical properties of Cu-BTC could be modified by growing it in bimetallic solutions.