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•A novel Ce-BTC MOF-derived CeO2 catalyst was prepared by thermal decomposition.•The CeO2 catalyst can be used for direct synthesis of DMC from CO2 and methanol.•The calcination ...atmosphere had great influence on the properties of obtained CeO2 catalysts.•The CeO2 by roasting in H2 atmosphere exhibited best catalytic performance.
As one of the most important green chemicals, dimethyl carbonate (DMC) has wide application prospects in electrochemistry, fuel additive, solvent and building block in organic synthesis. The effective utilization of CO2 to synthesize DMC has been proved to be highly advantageous. In this study, a series of Ce-BTC MOF-derived nanorod CeO2 catalysts for the direct synthesis of DMC from CO2 and methanol were prepared via complexation reaction at room temperature and then thermal decomposition under different atmospheres. The calcination atmosphere had great influence on the structure and catalytic properties of obtained CeO2 catalysts. The CeO2 derived from calcination of Ce-BTC at 500 °C under H2 atmosphere exhibited higher specific surface area, oxygen vacancy concentration and CO2 adsorption capacity. And thus, its DMC yield was up to 6.332 mmol/gCeO2 within 4 h, much higher than that of commercial nano CeO2 and other as-prepared catalysts in absence of dehydrating agents.
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•Cu-BTC acted as a precursor in successful CuNiN@C fabrication.•Doping of Ni and N enhanced the stability of material.•CuNiN@C worked as adsorptive bifunctional catalyst on ...norfloxacin degradation.•OH was the main contributor to norfloxacin oxidation.•The possible norfloxacin degradation ways were proposed.
In this study, calcined Cu-based metal-organic frameworks impregnated with nickel nitrate and pyrrole (CuNiN@C) with better stability and degradation performance was synthesized by doping of both Ni and N. Coupling with peroxymonosulfate (PMS), CuNiN@C worked as adsorptive bifunctional catalyst in effectively degradation of norfloxacin (NFX). Scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), transmission electron microscope (TEM), Selected area electron diffraction (SAED), High resolution transmission electron microscope (HRTEM) and X-ray diffraction (XRD) were applied for the preliminary characterization of the synthesized material to reveal the complete retention of the octahedral particle shape and successful doping of nitrogen. The results showed that over 80% NFX (5 mg/L) was degraded in 30 min with CuNiN@C (0.2 g/L) and PMS (2 mmol/L), and the reusability of CuNiN@C in four cycles did not significantly deteriorated, which was attributed to Ni doping. The mechanism of NFX degradation was separated into two parts: adsorption of CuNiN@C and activation of PMS. CuNiN@C adsorption followed a pseudo-second order rate model (R2 = 0.99), and nitrogen doping caused multiple electron-withdrawing functional groups in order to achieve chemisorption. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and N2 adsorption of both the pre-test and post-test CuNiN@C were adopted in the adsorption mechanism investigation. Meanwhile, as the activate sites of CuNiN@C, Cu and Ni responded to the PMS activation, and three radicals may be generated during the activation. Radical quenching experiments and Electron Paramagnetic Resonance (EPR) illustrated that the hydroxyl radical (OH) plays a major role in NFX oxidation, which was confirmed by the effect of pH value experiment. According to results of the liquid chromatograph linked to a mass spectrometer (LC-MS), possible degradation pathways are proposed: the substitution reactions and elimination reactions on both quinolone and benzene rings, the destruction of the piperazinyl group and the opening of the quinolone ring. This study provides new insight into the fabrication and application of the CuNiN@C/PMS system as antibiotic pollution remedy in aquatic environment.
A series of octahedral structure Cu-BTC derivatives were successfully achieved through direct calcination of copper based metal organic framework Cu-BTC under different atmosphere (CO reaction gas, ...oxidizing gas O2, reducing gas H2, inert gas Ar). The Cu-BTC derivatives were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), laser Raman spectroscopy (LRS), N2 adsorption-desorption isotherm, element analysis, H2-temperature program reduction (H2-TPR) and X-ray photoelectron spectroscopic (XPS). It is found that Cu-BTC derivative derived from MOF calcined under reaction gas/O2 (Cu-BTC-CO/Cu-BTC-O) only retain Cu2O and CuO species. In addition, a weak Cu-BTC structure and Cu particles were observed on Cu-BTC derivative derived from MOF calcined under H2 (Cu-BTC-H). Obviously differently, Cu-BTC derivative derived from MOF calcined under Ar (Cu-BTC-Ar) still retains good MOF structure. The catalytic performance for CO oxidation over Cu-BTC derivatives was studied. It was found that Cu-BTC-CO showed a smaller specific surface area (8.0m2/g), but presented an excellent catalytic performance, long-term stability and cycling stability with a complete CO conversion temperature (T100) of 140°C, which was ascribed to the higher Cu2O/CuO ratio, good low temperature reduction behavior and a high quantity of surface active oxygen species.
A series of octahedral structure Cu-BTC derivatives were successfully achieved through direct calcination of copper based metal organic framework Cu-BTC under different atmosphere. Display omitted
•Octahedral structure Cu-BTC derivatives were prepared by a simple method.•Cu-BTC derivative obtained at calcined temperature of reaction gas displays high activity.•Cu2O/CuO ratio and low temperature reduction behavior affect catalytic activity.
Using a green and simple route with ultrasound illumination, for synthesizing tacrine analogues was considered. Use of Cu3(BTC)2 as an environment-friendly for improved synthesis of ...oxazolo5,4-bquinoline derivatives was described under mild and clean conditions, and was compared with catalysis activity of H-BEA, (Al)SBA-15, Cu(NO3)2·3H2O and H3BTC. The results of this study indicate that the active sites in the Cu3(BTC)2 for synthesis of cycloheptaboxazolo4,5-epyridine are mainly copper atoms and the role of Brǿnsted acid organic ligand in the MOF is negligible.
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Using a green and simple route with ultrasound illumination, atmospheric pressure and room temperature, for synthesizing tacrine analogues in the presence of Cu3(BTC)2 as an environment-friendly and economically catalyst was considered. Cu3(BTC)2 is one of the heterogeneous catalysts on hand capable of being employed, in the Friedländer reaction, whenever 5-amino-4-cyano-2-phenyl-1,3-oxazole and appropriately substituted carbonyl derivatives under conventional and ultrasonic irradiation. The results of this study indicate that the active sites in the Cu3(BTC)2 for synthesis of cycloheptaboxazolo4,5-epyridine are mainly copper atoms and the role of Brǿnsted acid organic ligand in the MOF is negligible. These procedures were properly arranged in order to provide the utmost yields in a short while. The crystal stability in the process of catalysis was investigated by various techniques such as XRD, BET and ICP that demonstrate excellent stability in reaction conditions.
Cyclic voltammetry and structure of Cu–MOF compared with glassy carbon (UGC) in 0.1M LiCl, prepared by tree different methods. Display omitted
► Differences in functionalization of Cu3(BTC)2 ...depending on synthetic conditions. ► Synthesis method impacts directly on the electrochemical behavior of Cu3(BTC)2. ► The electrochemical behavior of MOF can be associated to presence of Cu2O. ► The reduction of copper ions into the structure occurs through two monoelectron steps.
For the construction of the metal–organic framework Cu3(BTC)2 (commonly known as MOF-199 or HKUST-1), three different synthesis strategies were employed: room temperature stirring (RT), solvothermal (ST) and ultrasonic assisted (US); which afforded the desired material in moderate yields. Several characterization techniques (XRD, FT–IR, SEM and TGA) showed that HKUST-1 was obtained in every method. However, there were found interesting differences in functionalization depending on the synthesis conditions which produced the same Cu3(BTC)2 host net but with different coordinative and bulk molecular guests. By XRD pattern analysis, it was possible to identify characteristic peaks of Cu2O in the ST obtained material as secondary phase, showing that this methodology is quite harsh giving place to this product, although the Cu3(BTC)2 complex was obtained in good yield. Regardless the energy source applied, in all three cases the desired Cu3(BTC)2 MOF was obtained. In order to determine if the method of synthesis impacts directly on the electrochemical behavior of de material, applied cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) were investigated. The electrochemical results have shown that the resistance to the faradic process increases in the following order: Cu–MOFUS, Cu–MOFRT and Cu–MOFST. This behavior can be associated to the presence of Cu2O in Cu–MOFST. However, the synthesized MOF at room temperature showed a major content of copper, which could be electrochemically transformed, as well as purity, in comparison with those obtained by solvothermal and ultrasonic assisted methods.
The principle of integral metal–organic framework (MOF) reconstruction is demonstrated for differently degraded HKUST‐1 via a facile, one‐step, solvent‐assisted treatment. Controlled MOF degradation ...by exposure to 77% humidity, liquid water, and diluted hydrochloric acid produces a mixture of non‐porous crystalline hybrid materials containing protonated linker and copper‐oxo species, which are then reconstructed back into high‐quality HKUST‐1 by contacting them with ethanol. X‐ray diffraction and sorption kinetics reveal a true memory effect of the system from completely degraded materials. The reconstruction approach is consequently extrapolated to gas‐ and liquid‐phase treatments in a fixed‐bed reactor with ethanol and ethanol/water mixtures for use in CO2 capture from a simulated pre‐combustion gas stream. Up to a maximum of 94% porosity and 85% CO2 sorption capacity can be recovered from a steamed material. A degradation‐reconstruction model is put forward based on X‐ray diffraction observations and structural analyses, microscopy, N2 sorption, thermogravitry–mass spectrometry and IR spectroscopy observations, particularly elucidating the influence of various degradation pathways on the reconstruction.
Reconstruction of water‐degraded HKUST‐1 back into the original material is demonstrated through solvent‐assisted liquid‐ and gas‐phase treatments. Up to 94% porosity and 85% CO2 sorption capacity could be recovered from a completely collapsed metal–organic framework. The degradation routes affect the physicochemical features and the kinetics of reconstruction. This method opens promising directions for the large‐scale application of these materials.
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Isoreticular bimetal M−Cu−BTC has considerable potential in improving the sulfides removal performance of Cu–BTC. Herein, three transition metals, namely, Zn2+, Ni2+ and Co2+, were ...assessed to fabricate M−Cu−BTC, a desirable isoreticular bimetal. Results demonstrated the feasibility of using Zn2+ to fabricate an isoreticular bimetallic Zn–Cu–BTC. The Zn2+ doping content of Zn–Cu–BTC was varied to investigate its influence on the hydrogen sulfide (H2S) and methyl sulfide (CH3SCH3) removal performance of Cu–BTC. The experimental results indicated that the sulfides removal performance of Zn–Cu–BTC increased and then decreased with increasing Zn doping content. The highest H2S and CH3SCH3 removal capacities of 84.3 and 93.9 mg S/g, respectively, were obtained when the Zn2+ doping content was 17%. The hybridisation of Zn and Cu in Zn–Cu–BTC induced a strong interaction between them. This interaction increased the binding energies of H2S and CH3SCH3 towards the Cu and Zn adsorption sites while weakening the bond order between Zn and Cu. The weakened bond order made the Zn–Cu bonds easier to form metal sulfides during desulfurization process, thereby synergistically enhancing sulphide removal.
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•A novel porous Ag@Cu-BTCIPA composite was synthesized by modifying Cu-BTC with isopropyl alcohol and silver.•Imidacloprid was adsorbed onto Cu-BTC, Cu-BTCIPA and ...Ag@Cu-BTCIPA.•Maximum adsorption attained by Ag@Cu-BTCIPA at pH 7 was 83.6%.•Kinetic studies for adsorption and release were performed.
Imidacloprid, which is harmful for humans as well as many other aquatic invertebrate species, is extensively present in water worldwide. Hydrophobic Cu-BTCIPA and a novel composite, Ag@Cu-BTCIPA, was synthesized for adsorption of imidacloprid from water. The synthesis of the composite and the increase in surface area and pore volume were confirmed by FTIR, XRD, SEM, and BET analysis. A comparative study of the adsorption efficiencies of the synthesized composites was performed. The maximum adsorption efficiency achieved was 83.6 % at pH 7 by the Ag@Cu-BTCIPA composite. Kinetic and isotherm analyses suggested multilayer chemisorption involving p-p conjugation and pore-filling mechanisms. Intra-particle diffusion was the rate limiting step. Release studies of imidacloprid from water showed that the percentage release amount was 90.2 % at 70 min. Kinetic analysis of the release process suggested release through chemisorption, with swelling-controlled release from the dosage form, corresponding to the super case II transport mechanism.
The vast discharge of methylene blue (MB) dye in industrial effluent, risks the ecological environment, thus making its removal unavoidable. Recently, metal organic frameworks (MOFs) due to their ...larger pore volume, surface area and easy synthesis have proved to be exceptionally promising materials for contaminant treatment. Based on 1,3,5-benzenetricarboxylic acid (BTC) as a modifier, a new composite material consisting of BTC and Zr-based MOF (UIO-66-BTC) was fabricated for the effective removal of MB from the effluent. Its synthesis and efficient application has been confirmed by characterization analysis. The influencing factors, adsorption isotherms, and adsorption kinetics of MB adsorption by adsorbent were studied. It was demonstrated that the removal rate of MB adsorption by UIO-66-BTC reached 98.45% and the adsorption amount reached 393.80 mg g−1 at temperature (298 K), pH 7, adsorbent dosage (0.5 g L−1), MB initial concentration (200 mg L−1), and contact time of 720 min, respectively. The maximum adsorption of MB by UIO-66-BTC was 20.827 times higher than that of UIO-66 (18.908 mg g−1). The experimental data fits with the pseudo-second-order kinetic model and Langmuir isotherm, implying that the adsorption process is a monolayer chemisorption process. The thermodynamic and regeneration experiments showed that the spontaneous process enhanced the adsorption of MB at lower temperatures and the adsorption efficiency of MB remained above 68% after five successive cycles. The mechanism of MB adsorption on adsorbents is mainly based on electrostatic interactions, pore filling, hydrogen bonding and π-π interactions. It is concluded that this new adsorbent can be effectively used to treat MB in effluents.
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•BTC modified Zr-based MOF (UIO-66-BTC) was prepared.•MB could be efficiently removed by UIO-66-BTC.•PSO kinetic model and Langmuir isotherms model were applicable to the adsorption of UIO-66-BTC for MB.•The removal rate of MB still above 68% after five regeneration cycle.
Protein kinases play crucial regulatory roles in the physiological activities in the human body. Understanding protein kinase activity and its inhibition is essential for the management of human ...diseases. Considering the limitations of the existing protein kinase-related analysis methods, the aim of the present study was to develop a fluorescent biosensor based on Eu(BTC) (H2O)6 (BTC = 1,3,5-Benzenetricarboxylic acid) for evaluating protein kinase activity and the relevant inhibitors. A fluorophore-labelled substrate polypeptide was phosphorylated under the catalysis of protein kinase. This phosphorylated peptide can be coordinated explicitly with the europium site of Eu(BTC) (H2O)6 to detect the protein kinase. The developed biosensor performed well, with a detection limit of 0.00003 U μL−1, and it showed good selectivity and universality. Protein kinase activity could also be detected in MCF-7 cells using this method. Furthermore, in terms of inhibitor screening using the Eu(BTC) (H2O)6-based sensor, both H-89 and ellagic acid were found to inhibit protein kinase activity with IC50 values of 1.09 and 19.88 nmol L−1, respectively. Overall, this biosensor has broad application prospects in monitoring and controlling protein kinase activity.
•A new biosensing platform for detecting PKA activity was established using Eu(BTC) (H2O)6.•Akt1 was selected to prove the universality of this biosensor for protein kinases.•This biosensor screened two common PKA inhibitors, H-89 and ellagic acid.•This method is helpful for monitoring and treating protein kinase-related diseases.
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