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•TiO2-Zn-BTC MOF photoanodes were fabricated via ultrasonic-assisted hydrothermal method.•TiO2-Zn-BTC MOFs exhibit reduced recombination rate, increased photoactivity and reduced ...charge-transfer kinetics.•I–V curves show that TiO2- Zn-BTC MOF(2%) has 1.01 mA/cm2 and photo-efficiency > 0.67 %.•Enhanced extraction of photogenerated electrons and holes of TiO2 at low Zn-BTC loadings.•Zn-BTC MOF has stabilizing effect on TiO2 for use in as photoanode.
This work reports on the effect of zinc(II)-benzene-1,3,5-tricarboxylate metal organic frameworks (Zn-BTC MOFs) towards enhancing the power conversion efficiency of titanium dioxide (TiO2) based dye-sensitized solar cells (DSSCs). Zn-BTC MOFs and TiO2 nanoparticles were synthesized via a modified hydrothermal method. This was followed by the addition of an extrinsic mixture of TiO2 powder and MOFs to form TiO2-Zn-BTC MOF(2%), TiO2-Zn-BTC MOF(4%) and TiO2-Zn-BTC MOF(6%) nanocomposites with varying concentrations. The structure, morphology, optical properties and thermal stability of the MOF powders were subsequently evaluated. XRD analysis demonstrated that the incorporation of MOFs into TiO2 decreases the crystallinity of TiO2 due to the poor crystalline structure of MOFs. The presence of the Ti-C bond and the induced redshift of the E1g peak suggesting the migration of electrons between TiO2 and MOFs was confirmed by FTIR and Raman spectroscopy, respectively. Microscopic studies showed the formation of irregularly shaped nanoparticles with a size range of 5–40 nm. Additionally, the BET surface area improved with an increase in Zn-BTC loadings, leading to the uniform dispersion of TiO2 nanoparticles in the nanocomposites. The optical properties of the nanocomposites were enhanced by the incorporation of Zn-BTC MOFs resulting to low band gap values. The TiO2-Zn-BTC MOF(2%) exhibited a lower band gap of 2.9 eV in comparison to TiO2-Zn-BTC MOF(4%) with a band gap of 3.1 eV and TiO2-Zn-BTC MOF(6%) which also had a band gap of 3.1 eV. Hence, TiO2-Zn-BTC MOF(2%) exhibited reduced recombination rates of the electron-hole pairs and increased photoactivity as confirmed by the photoluminescence (PL) spectroscopy data, as well as reduced charge-transfer kinetics shown by electrochemical impedance results. The I–V results showed that TiO2-Zn-BTC MOF(2%) has a strong ability to act as an effective electron transporter which significantly enhanced the photoefficiency of TiO2 thus leading to better photoanodes for DSSCs.
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•Multiscale design of 3D MOF (M−BTC, M: Cu, Co, Ni) was demonstrated via PLAL.•Studied intrinsic properties on electrocatalytic active-states for overall water splitting.•Co-BTC ...achieve low η10 of 437 and 370 mV for HER and OER, respectively.•Require only 2.03 V @ 10 mA/cm2 for Co–BTC ∥ Co–BTC full electrolysis system.•Electronic effect implying on structural stability and long-term durability.
Multiscale structural engineering of high-performance bifunctional electrocatalysts to influence hydrogen and oxygen evolution reactions (HER and OER) has a significant role in overall water splitting. Thus, we successfully designed a new strategy and synthesized transition-metal-based 3D metal–organic framework (MOF) materials having various architectures, namely, Cu–BTC, Co–BTC, and Ni–BTC, by pulsed laser ablation in dimethylformamide. The coordination between the metal and carboxylate moieties of the ligand, crystalline structure, phase purity, morphology, thermal stability, and oxidation states were illustrated using physical characterization techniques. Further, intrinsic properties of the MOF materials were studied using electrocatalytic reactions toward HER and OER in an alkaline medium. Among the synthesized MOF materials, the Co–BTC electrocatalyst showed a very low overpotential of 437 mV toward HER at a constant current density of 10 mA cm−2 in 1.0 M potassium hydroxide. The derived Tafel slope and Rct values are 115.1 mV dec−1 and 2.77 Ω cm−2, respectively. Similarly, OER studies reveal that the Co–BTC MOF showed robust activity with low overpotential of 370 mV at 10 mA cm−2. Finally, the optimal Co–BTC MOF electrode required 2.03 V of cell potential to deliver 10 mA cm−2 in a dielectrode (Co–BTC ∥ Co–BTC) electrolysis system with long-run stability. The present report reveals a new possibility for the innovation in robust HER and OER bifunctional electrocatalysts using nonprecious metallic MOF materials.
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•BTCMOFs were deposited on cellulose extracted from banana fibbers.•Produce MOFs composites used to remove creatinine and p-cresyl sulfate from blood.•MOFs composites are suitable for ...hemodialysis with high absorption and recyclability.•MOFs composites have potential antimicrobial activity.
The accumulation of uremic toxins in the human body presents a fatal issue that leads to the development of chronic kidney disease. The effective removal of these toxins from the bloodstream is crucial for enhancing the efficacy of hemodialysis and improving the survival rate. A comprehensive understanding of the interactions between an adsorbent and the uremic toxins is vital in the development of efficient materials for the elimination of these hazardous compounds. In this study, we investigate the adsorption behavior of various toxins, namely cresol sulfate, and creatinine, using banana cellulose and its modified form with MOFs, namely Ni-BTC, Cu-BTC, and Co-BTC. The adsorption behavior is characterized using the Langmuir and Freundlich models. The analysis reveals that the Langmuir model provides a better fit to the isotherm data compared to the Freundlich model. Furthermore, the adsorption kinetics data indicate that both banana cellulose and its modified form with MOFs adhere to the pseudo-second-order rate models rather than the pseudo-first-order model. The capacities for adsorption of cresol sulfate by banana cellulose, Ni-BTC@cellulose, Cu-BTC@cellulose, and Co-BTC@cellulose were measured to be 115, 402, 509, and 577 mg/g, respectively. Conversely, the capacities for adsorption of creatinine were found to be 166, 514, 605, and 704 mg/g, respectively. The underlying mechanism of adsorption is contingent upon the van der Waals interactions and π–π interactions. Furthermore, even after undergoing five cycles, the removal efficiency for cresol sulfate and creatinine remained at 88 % and 85 %, respectively. These findings demonstrate the renderability of MOFs@cellulose. The antimicrobial activity of the prepared MOFs was recorded for all MOFs composites against tested pathogenic microbes. Additionally, the MOFs@cellulose exhibited a satisfactory level of blood compatibility. Consequently, these exceptional MOFs@cellulose present a promising opportunity for reducing costs associated with clinical hemodialysis.
This work presented the synthesis of Ni-based metal-organic framework material with a paddle-wheel structure Ni3(BTC)2 (Ni-BTC) and its application in thiophene (TP) adsorption from gasoline ...distillate by batch method. Adsorption isotherms of TP, cyclohexene, and toluene in cyclohexane onto Ni-BTC were conducted at 298–308 K to interpret the different effect of cyclohexene and toluene on TP adsorption. The results showed that, compared with cyclohexene, toluene addition in model gasoline led to a more evident decline in sulfur capacity of Ni-BTC, which is opposite to isostructural HKUST-1. The adsorption isotherms of TP, cyclohexene and toluene fit Langmuir model, S-type model and Temkin model well, respectively, indicating that the adsorption mechanisms of TP and the two competitors are different from one another. The adsorption capacities on Ni-BTC followed the order of cyclohexene < toluene < TP at the same equilibrium concentrations, implying the order of the adsorption affinities, which is in good agreement with the different extent of influence by the two competitors. The enthalpy of TP adsorption on Ni-BTC was estimated to be −80.01 kJ/mol, almost twice that on HKUST-1. The poor reusability of Ni-BTC in batch experiment, which is owing to its sensitivity to the air, can be prevented from regenerating used Ni-BTC in fixed-bed reactor by N2 flow. The difference between Ni-BTC and HKUST-1 in maximum adsorption capacity (q0), ΔH of TP adsorption, and stability demonstrates that the central metal in isostructural MOFs plays a key role in adjusting the desulfurization performance, which may open up a potential avenue for the development of MOF-based adsorbents with superior desulfurization performance.
The adsorption affinities on Ni-BTC followed the order of cyclohexene < toluene < thiophene at the same equilibrium concentration at 298 K. Display omitted
We report in this work, a new method for the determination of captopril by differential pulse voltammetry using a glassy carbon electrode modified with a copper metal‐organic framework (H‐Kust‐1 or ...Cu3(BTC)2 or Cu‐BTC), immobilized on the surface by a copolymer of acrylamide and sodium acrylate. This compound is detected by the formation of a copper(II)‐captopril complex that is observed in an oxidation potential at ca. +0.28 V vs. Ag/AgCl. A linear dynamic range is obtained for a captopril concentration of 0.5 μM to 7.0 μM and the voltammetric response is highly reproducible within 3.52 % error. The sensitivity of 9.71±0.37 nA μM−1 and the limit of detection of 0.20±0.01 μM make this methodology highly applicable for practical applications. The determination of captopril in a commercial pharmaceutical sample showed a recovery of 93.3 %.
We fabricate a N/P co-doped octahedral carbon matrix derived from Cu-MOF to encapsulate Cu3P nanoparticles by a two-step process of carbonization and phosphating. The novel shell carbon structure ...inhibits the volume change of Cu3P nanoparticles, prevents the agglomeration of nanoparticles in the process of charge and discharge, and ensures the integrity of the electrode. The results of DFT calculation show that Cu3P@NPC hetero-structure has excellent lithium storage capacity. Therefore, this octahedral Cu3P@NPC composite, as anode material for LIBs, shows a good rate performance and cycling performance.
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•A N/P co-doped octahedral carbon encapsulated Cu3P composite was synthesized.•A PVP assisted pyrolysis strategy can effectively stabilize the structure of the octahedron.•Density functional theory (DFT) calculations confirm the underlying mechanism of the beneficial effect of Cu3P@NPC.•High lithium-storage capacity of 336.4 mA h g−1 is retained over 1000 cycles at 1 A g−1.
The large volume expansion and poor electrical conductivity of copper phosphide (Cu3P) during the cycle limit their further application as anode of lithium-ion batteries. Therefore, polyvinylpyrrolidone (PVP) modified Cu3(BTC)2-derived (BTC = 1, 3, 5-Benzentricarboxylic acid) in-situ N/P-co-doped Octahedron carbon encapsulated Cu3P nanoparticles (Cu3P@NPC) are successfully prepared through a two-step process of carbonization and phosphating. The N/P-co-doped Octahedron carbon matrix improves the conductivity of Cu3P and moderates the volume expansion during the lithiation/delithiation process. Meanwhile, the interaction between the Cu3P and the doped carbon matrix is methodically explored by using density functional theory (DFT). Through the analysis of the partial charge density, the density of states and the Bader charge, and the calculation results verify the correctness of the experimental observation results, that is, Cu3P@NPC has good electrochemical performance. The results show that Cu3P@NPC, as the anode of Lithium-ion batteries, has excellent electrochemical performance: it exhibits satisfactory rate performance (251.9 mAh g−1 at 5.0 A g−1) and excellent cycle performance (336.4 mAh g−1 at 1 A g−1 over 1000 cycles). This article provides an effective strategy for the encapsulation of metal phosphide nanoparticles in a doped carbon matrix.
In this study, Cu3(BTC)2 and Ni1.5-Cu1.5(BTC)2 were synthesized in the presence of microwave irradiation. The morphology and the structure of the prepared MOFs were characterized by XRD, TEM, TGA, ...FTIR, Raman, and nitrogen adsorption/desorption methods. The adsorption activities of the samples towards the phenols from aqueous solutions were achieved including kinetic and equilibrium approaches with different nonlinear models for modeling. The experimental data clarified that the adsorption of phenols on Cu3(BTC)2 and Ni1.5Cu1.5(BTC)2 had been processed via a pore-filling mechanism. Thermodynamic parameters were also determined. Furthermore, a three levels-four factor half-factorial design was successfully employed for experimental design and analysis of the results through response surface methodology (RSM). The significance of the independent variables was tested and optimized by the analysis of variance (ANOVA) and t-test statistics. The optimum pH, adsorbent dose, and temperature were found to be 5.0, 1 g/l, and 30 °C, respectively, for both samples. Under these conditions, the predicted removal efficiency of 50 mg/l phenols was found to be 71.32% (35.65 mg/g) and 78.95% (39.47 mg/g), respectively.
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•Cu3(BTC)2 and Ni1.5-Cu1.5(BTC)2 were synthesized and characterized.•The affinities of MOFs towards the phenols in the aqueous medium were evaluated.•NiCu MOF removed ∼79% of 50 mg/L phenols at the optimum experimental conditions.
The nanocomposite of CoFe2O4@ Cu3(BTC)2 was synthesized based on the Pechini sol–gel technique. CoFe2O4 and Cu3(BTC)2 could be seen in the XRD pattern. SEM and TEM images contain some similar ...nanoparticles with uniform size and shape. Photoluminescence behavior of the composite compound was better than that of CoFe2O4 nanoparticles. Incredible values were measured for specific surface area and pore volume which are 438 m2/g and 0.67 cm3/g, respectively. The magnetic response of the nanocomposite was achieved about 20 emu/g, which is high enough to utilize for collecting this material after applying in different situations.
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An exquisite method with high efficiency has been utilized to synthesized a composite material based on Cu3(BTC)2 as a metal–organic framework (MOF) as well as CoFe2O4 nanoparticles. This is a novel method and presented throughout this manuscript for the first time. For this aim, the composite compound was fabricated via Pechini sol–gel method by using iron nitrate, methacrylic acid, ethanol, copper nitrate, and trimesic acid. The obtained compound due to its magnetic properties could be an appropriate candidate for smart materials, and medical applications.
The results showed that the composite compound contains both Cu3(BTC)2 as a MOF and also CoFe2O4. The obtained features in microscopic observations approved the formation of homogenous nanoparticles which are not similar to column-shape-particle of the MOF. Although UV absorption of the composite compound declined, both photoluminescence and specific surface area improved rather than CoFe2O4 nanoparticles. Such a compound with 438 m2/g surface area, 0.67 cm3/g pore volume, and tremendous magnetic response of 20 emu/g seems to be valuable enough for more consideration.
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•Cu-BTC@CuS@CeO2 double p-n heterojunction hollow octahedrons were fabricated.•Cu-BTC@CeO2 and hollow structure were concurrently realized by one-step process.•The catalyst exhibited ...high visible light absorption and multipath fast charge transfer.•The catalyst provided a remarkable Vis/NIR light oxidation activity of amines to imines.
Hollow heterostructured catalysts have been widely investigated and applied in photocatalytic organic reactions. However, achieving hybrid catalysts with optimized hollow structure and controllable components is still a challenge. Herein, Cu-BTC@CuS@CeO2 ternary heterostructure hollow octahedrons were designed and prepared using a copper-based metal–organic framework (Cu-BTC) as both copper source and template. A thin CeO2 nanolayer was first formed and covered on the prepared Cu-BTC octahedron surface through a hydrothermal process. In the meanwhile, the Cu-BTC octahedrons were controllably etched in this hydrothermal process, leading to the formation of Cu-BTC@CeO2 hollow octahedron. The following sulfidation reaction produced Cu-BTC@CuS@CeO2 double p-n heterojunction hollow octahedrons. Benefiting from the novel hollow octahedron double p-n heterojunctions, excellent visible-near infrared light absorption, and fast charge transfer and separation, the obtained Cu-BTC@CuS@CeO2 hollow octahedron hybrid catalyst exhibited a significantly higher photocatalytic activity toward the oxidative coupling of amines to imines at room temperature under visible-near infrared light irradiation compared to the control single component catalysts (Cu-BTC, CeO2, and CuS) and binary hybrid catalysts (Cu-BTC@CeO2, Cu-BTC@CuS, and CuS@CeO2). The enhanced charge transfer at the double p-n heterojunction was discussed. Meanwhile, the photocatalytic oxidation products and reaction mechanism were investigated by surface-enhanced Raman spectroscopy, gas chromatography-mass spectrometry, and pyridine adsorption FT-IR spectroscopy. This work presents a promising strategy for the design of multi-component hollow heterostructure catalysts.
•Cu-BTC@CuSe@TiO2 hollow octahedrons with double p-n heterojunction were fabricated.•Cu-BTC@TiO2 heterojunction and hollow structure were acquired by one-step process.•The catalyst exhibited ...excellent charge separation and high visible light absorption.•The catalyst provided efficient CO2 photoreduction and high CO selectivity.
Solar-driven photocatalytic conversion of CO2 into high-value-added fuels has attracted widespread attention. However, the relatively low conversion efficiency and product yield severely limited photocatalytic applications. In this work, binary Cu-BTC@TiO2 catalysts with adjustable inner cavity were prepared using copper-based metal organic framework (Cu-BTC) octahedrons as substrate via a solvothermal reaction. In this process, the inner Cu-BTC octahedrons can be controllably etched into a hollow octahedral structure in the presence of HF. Subsequently, the Cu-BTC@CuSe@TiO2 hollow octahedrons (HOs) were fabricated by selenization reaction and exhibited various properties such as abundant active sites for CO2 adsorption and reduction reactions, shortened charge transfer distance to prevent electron-hole recombination, and internal reflection/scattering effects to improve solar light utilization. Moreover, the formed dual p-n heterostructures between p-type CuSe and n-type semiconductors (Cu-BTC and TiO2) effectively promote spatial separation and migration of charge carriers. The synergistic effect of these advantages makes the optimized Cu-BTC@CuSe@TiO2 HO catalyst exhibit remarkable CO2 photoreduction performance with a CO production rate of 72.3 μmol h−1 g−1 and near 100 % selectivity. This work opens a new pathway for designing highly active photocatalysts with excellent product selectivity.
