•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.
In this work, a new MOF Eu-BTC-BDC-NH2 (BTC = benzene-1,3,5-tricarboxylate, BDC-NH2 = 2-aminoterephthalic acid) was synthesized by a facile and energy-efficient process, and can be utilized as a ...highly sensitive and selective ratiometric fluorescence probe for phosphate (Pi). The produced Eu-MOF had two emission peaks at 425 nm and 617 nm, which came from the BDC-NH2 ligand and energy transfer effect between the two ligands and Eu3+, respectively. When contact with Pi, due to the ultra-high affinity between Eu3+ and the oxygen atoms in Pi, part of the ligands were replaced and P-O-Eu bonds formed. Accordingly, the energy transfer effect was weakened, and the fluorescence intensity at 617 nm reduced, however, the peak at 425 nm increased. Based on this, a Pi ratiometric fluorescence platform with excellent performance was established with a low detection limit (LOD) of 0.07 μM and superior selectivity for 19 common ions and 6 phosphate-containing molecules. In addition, the sensor achieved satisfactory results in the detection of environmental water samples. Finally, a portable detection kit based on hydrogel-MOFs was successfully constructed by combining with a smartphone, which can realize on-site monitoring of Pi.
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•A new MOF Eu-BTC-BDC-NH2 was synthesized by a facile and energy-efficient process.•The generated Eu-MOF can be used as a ratiometric fluorescence probe for phosphate.•The established sensor had high sensitivity and excellent selectivity.•A detection kit based on hydrogel-MOFs was built to realize on-site monitoring of Pi.
In-situ growth of CsPbBr3 nanocrystal into Eu-BTC was realized for synthesis of dual-emission CsPbBr3@Eu-BTC by a facile solvothermal method, and a novel ratiometric fluorescence sensor based on the ...CsPbBr3@Eu-BTC was prepared for rapid, sensitive and visual detection of Hg2+ in aqueous solution. The transmission electron microscopy (TEM), X-ray diffraction pattern (XRD), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analysis were used to verify the successful incorporation of CsPbBr3 into the Eu-BTC. Meanwhile, the CsPbBr3@Eu-BTC nanocomposite maintained high fluorescence performance and stability in aqueous solution. After adding Hg2+, the green fluorescence of CsPbBr3 was quenched and the red fluorescence of Eu3+ remained unchanged, while the color changed from green to red obviously. The occurrence of dynamic quenching and electron transfer were verified by fluorescence lifetime, Stern-Volmer quenching constant and XPS analysis. The ratiometric fluorescence sensor shows high analytical performance for Hg2+ detection with a wide linear range of 0–1 μM and a low detection limit of 0.116 nM. In addition, it also shows high selectivity for the detection of Hg2+ and can be successfully applied to detect Hg2+ in environmental water samples. More importantly, a novel paper-based sensor based on the CsPbBr3@Eu-BTC ratiometric probe was successfully manufactured for the visual detection of Hg2+ by naked eyes. This new type of ratiometric fluorescent sensor shows great potential for applications in point-of-care diagnostics.
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•Double emission CsPbBr3@Eu-BTC was synthesized by a facile in-situ growth method.•The CsPbBr3@Eu-BTC maintain high fluorescence and stability in aqueous solution.•CsPbBr3@Eu-BTC based paper device can realize visual and rapid detection of Hg2+.•The ratiometric sensor was used for actual water sample Hg2+ detection.
Magnetite nanoparticles@Fe-BTC composite material was synthesized by a solvothermal method, where magnetite nanoparticles were added during the synthesis and was characterized by different analytical ...techniques analytical such as XRD, Raman and FTIR spectroscopy, and nitrogen physisorption at 77 K. Magnetite nanoparticles into Fe-BTC composite material was used in the adsorption of metals ions such as copper (Cu(II)), mercury (Hg (II)), arsenic (As (III)), and lead (Pb (II)). The experimental data of the adsorption of Cu(II), As (III), and Pb (II) metals ions showed a better fit to Langmuir isotherm model, while for the Hg (II) ion adsorption was observed a better adjusts to Temkin isotherm model. The kinetic pseudo-second-order model is the one that better describes the experimental data in all metal ions. The composite material showed a maximum adsorption capacity of 55 mg/g, 57 mg/g, 147 mg/g, and 155 mg/g for Cu (II), As (III), Pb (II), and Hg (II), respectively which was considerable. The adsorption selective for composite material in the mixed metal solution followed the order of Cu (II)> Pb (II) > Hg (II) > As (III). Therefore, composite material could be a good alternative as adsorbent material for the remediation of contaminated water by heavy metals.
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•Fe3O4@Fe-BTC show a good adsorption performance and very considerable for the adsorption of heavy metal ions.•In the incorporation of Fe3O4 NPs in Fe-BTC were not observed change very significative in its structure of the MOF.•Fe3O4@Fe-BTC show a good recyclability after of three adsorption cycles for Cu (II), As (II) and Pb (II) metal ions.
•Cu3(BTC)2-doped AC was first studied in air-cathode MFC filed.•The high specific area and micropores greatly affected catalytic reaction rate.•The 3D framework and high Lewis acidity also ...accelerated the ORR in MFC.•The MPD was 1772±15mWm−2, higher than that of AC electrode.
Metal-organic framework Cu3(BTC)2, prepared by an easy hydrothermal method, was used as the oxygen-based catalyst in microbial fuel cell (MFC). The maximum power density of Cu3(BTC)2 modified air-cathode MFC was 1772±15mWm−2, almost 1.8 times higher than the control. BET results disclosed high specific surface area of 2159.7m2g−1 and abundant micropores structure. Regular octahedron and porous surface of Cu3(BTC)2 were observed in SEM. XPS testified the existence of divalent copper in the extended 3D frameworks, which importantly acted as the Lewis-acid sites or redox centers in ORR. Additionally, the total resistance decreased by 42% from 17.60 to 10.24Ω compared with bare AC electrode. The rotating disk electrode test results showed a four-electron transfer pathway for Cu3(BTC)2, which was crucial for electrochemical catalytic activity. All the structural and electrochemical advantages make Cu3(BTC)2 a promising catalyst for ORR in MFC.
In view of the unsatisfactory synergy between plasma technology and catalyst, a series of M-BTC MOFs (M=Mn, Cu, Ce) were introduced to couple with non-thermal plasma using for toluene degradation. ...M-BTC MOFs containing multi-carboxylic groups were successfully synthesized and presented the excellent crystallinity, morphology and thermal stability. DBD-catalysis systems presented the more excellent toluene degradation performance than single DBD alone system. Due to the porous structure and the multivalent form of manganese, the highest toluene degradation efficiency of 96.27%, the energy efficiency of 22.32 g/kW·h, the CO2 selectivity of 53.5% and the mineralization degree of 70.17% were acquired for DBD coupled with Mn-BTC under SED of 766.35 J/L. Besides, DBD/Mn-BTC had the lowest ozone and NOx production. Moreover, the toluene degradation mechanism was analyzed by plasma emission spectra analysis, XPS spectra and GC-MS diagram analysis. It indicated plasma discharge can produce abundant free radicals and reactive species to decompose toluene firstly, and the residual toluene and intermediates in the gas can be then adsorbed on Mn-BTC and further oxidized by metal active species. Furthermore, more reactive oxygen species will be generated by activating ozone through Mn-BTC, which was beneficial for toluene degradation.
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The CuS(x wt%)@Cu‐BTC (BTC = 1,3,5‐benzenetricarboxylate; x = 3, 10, 33, 58, 70, 99.9) materials are synthesized by a facile sulfidation reaction. The composites are composed of octahedral ...Cu3(BTC)2·(H2O)3 (Cu‐BTC) with a large specific surface area and CuS with a high conductivity. The as‐prepared CuS@Cu‐BTC products are first applied as the anodes of lithium‐ion batteries (LIBs). The synergistic effect between Cu‐BTC and CuS components can not only accommodate the volume change and stress relaxation of electrodes but also facilitate the fast transport of Li ions. Thus, it can greatly suppress the transformation process from Li2S to polysulfides by improving the reversibility of the conversion reaction. Benefiting from the unique structural features, the optimal CuS(70 wt%)@Cu‐BTC sample exhibits a remarkably improved electrochemical performance, showing an over‐theoretical capacity up to 1609 mAh g−1 after 200 cycles (100 mA g−1) with an excellent rate‐capability of ≈490 mAh g−1 at 1000 mA g−1. The outstanding LIB properties indicate that the CuS(70 wt%)@Cu‐BTC sample is a highly desirable electrode material candidate for high‐performance LIBs.
CuS@Cu‐BTC composites are used as anode materials for lithium‐ion batteries for the first time, which exhibit improved Li‐ion storage abilities originating from the synergistic effect between the Cu‐BTC and nano‐CuS components.
Development of low-energy-consumption and low-cost process to prepare high-performance uncalcined MOF-based electrode materials is in line with the concept of green synthesis. We present here an ...uncalcined strategy of reorganizing the nano-sized MOF into a stable structure by anion intervention and doping with conductive substances to improve the conductivity. Three MOF electrode materials of Co-BTC nanoparticles (CBN), Co-BTC microspheres (CBM) and CNTs@Co-BTC microspheres (CCBM) have been prepared by a one-step approach of solvothermal. Results reveal that the introduction of phosphomolybdic acid (POM) can induce Co-BTC nanoparticles self-assemble into microspheres, which can provide CBM a superior specific capacitance compared to CBN. And doping with CNTs can further improve the electrochemical performance in term of the capacitance. Consequently, CCBM holds the highest specific capacitance as 553.3 F g−1 at 1 A g−1, and keeps an outstanding cyclic stability that retention of capacitance after 5000 cycles is around 90%.
This study aimed to present a new method combined of needle trap devices (NTDs) packed with the Zn3(BTC)2 metal-organic framework (Zn-MOF) as a sorbent, for the sampling and analysis of polycylic ...aromatic hydrocarbons (PAHs) in the air for the first time. The electrochemical method was used to synthesize Zn-MOF sorbent packed inside 22 gauge needle trap. This method was investigated in the laboratory under different condition and applied in the field to determination of PAHs in air. In order to make different concentrations of PAHs in air, a glass chamber under temperature of 120 °C was used. The optimization of the desorption conditions and breakthrough volume was accomplished using the response surface method and Design-Expert software (version 7). According to the results, the best desorption temperature was obtained as 379 °C in 9 min, the limit of detection and limit of quantification for the analytes under investigation were within the ranges of 0.011–0.021 and 0.03–0.07 mg/m3, respectively. Moreover, repeatability and reproducibility of the method were estimated in the ranges of 3.6–9.9 and 5.3–24.1, respectively. By storing the needles at 4 °C, no significant reduction was observed in the amount of analytes after 60 days (P > 0.05). It could be concluded that NTD: Zn-MOF is a reliable and high collection efficiency method had a suitable performance in the sampling of PAHs, compared to the National Institute for Occupational Safety and Health (NIOSH)-5515 method.
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•Zn3(btc)2 was firstly proposed and employed for PAHs recognition in air.•Zn3(btc)2 was used in needle trap devices (NTDs) as a solvent less method and reuse several times.•The optimization of the desorption conditions and breakthrough volume was accomplished using the Design-Expert software.•NTD: Zn-MOF is a suitable performance in the sampling of PAHs, compared to the NIOSH- 5515 method.•Advantages of electrochemical synthetic include solventless, high purity, ambient temperature, short synthesis time.
There is no effective environmental treatment strategy that does not include monitoring for pharmaceutical compounds in environmental and biological fluids. The widespread presence of ...pharmaceutical-based pollutants in water sources is a significant public health concern. The treatment process relies heavily on maintaining a stable digoxin concentration in bodily fluids. Finding the correct dose for this medication appears to be crucial. In this research, an easy and high sensibility electrochemical sensor was developed to determine digoxin based on a paste electrode (CPE) that was modified with Cu-BTC MOF and ion liquid ((IL); 1-Methyl-3-Butyl-imidazolinium bromide in this case) using voltammetric methods in 0.1 M phosphate buffer solution (PBS) at pH 5.0. The sensor's selectivity was significantly increased by using Cu-BTC MOF and IL to detect digoxin. The characteristics of the electrode modifiers were evaluated by SEM, XRD and EDS techniques. The LDR was found to be 0.1–40 μM and the LOD of 0.08 μM, respectively.
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•Introduced of Coupled Cu-BTC MOF with ionic liquid as catalysts.•Electrochemical sensor for precise detection of digoxin.•Analysis and monitoring of digoxin in pharmaceutical and environmental samples.
