Titanium Metal Organic Framework Research Articles

Optimizing Photoelectrochemical UV Imaging Photodetection: Construction of Anatase/Rutile Heterophase Homojunctions and Oxygen Vacancies Engineering in MOF-Derived TiO2.

Self-powered photoelectrochemical (PEC) ultraviolet photodetectors (UVPDs) are promising for next-generation energy-saving and highly integrated optoelectronic systems. Constructing a heterojunction is an effective strategy to increase the photodetection performance of PEC UVPDs because it can promote the separation and transfer of photogenerated carriers. However, both crystal defects and lattice mismatch lead to deteriorated device performance. Here, we introduce a structural regulation strategy to prepare TiO2 anatase-rutile heterophase homojunctions (A-R HHs) with oxygen vacancies (OVs) photoanodes through an in situ topological transformation of titanium metal-organic framework (Ti-MOF) by pyrolysis treatment. The cooperative interaction between A-R HHs and OVs suppresses carrier recombination and accelerates carrier transport, thereby significantly enhancing the photodetection performance of PEC UVPDs. The obtained device realizes a high on/off ratio of 10,752, a remarkable responsivity of 24.15 mA W-1, an impressive detectivity of 3.28 × 1011 Jones, and excellent cycling stability. More importantly, under 365 nm light illumination, a high-resolution image of "HUST" (the abbreviation of Harbin University of Science and Technology) was obtained perfectly, confirming the excellent optical imaging capability of the device. This research not only presents an advanced methodology for constructing TiO2-based PEC UVPDs, but also provides strategic guidance for enhancing their performance and practical applications.

Decoration of viscose fibers with silver nanoparticle-based titanium-organic framework for use in environmental applications.

To effectively remove pharmaceuticals, nitroaromatic compounds, and dyes from wastewater, an efficient multifunctional material was created based on silver nanoparticles (Ag) and MIL-125-NH2 (MOF) immobilized on viscose fibers (VF) as a support substrate. Firstly, silver nanoparticles (Ag) were immobilized on the surface of viscose fibers (VF) via in situ synthesis using trisodium citrate (TSC) as a reducing agent to create (VF-Ag). Then, VF and VF-Ag were decorated with the titanium metal-organic framework MIL-125-NH2 (MOF) to create VF-MOF and VF-Ag-MOF. The influence of VF-Ag, VF-MOF, and VF-Ag-MOF on the sonocatalytic or sonophotocatalytic degradation of sulfa drugs was investigated. The results show that VF-Ag-MOF showed excellent sonocatalytic and sonophotocatalytic activity towards the degradation of sulfa drugs compared to VF-Ag and VF-MOF. Furthermore, sonophotodegradation showed a dramatic enhancement in the efficiency of degradation of sulfa drugs compared to sonodegradation. The sonophotodegradation degradation percentage of sulfanilamide, sulfadiazine, and sulfamethazine drugs in the presence of VF-Ag-MOF was 65, 90, and 95 after 45min of ultrasonic and visible light irradiation. The catalytic activity of VF-Ag, VF-MOF, and VF-Ag-MOF was evaluated through the conversion of p-nitrophenol (4-NP) to p-aminophenol (4-AP). The results demonstrate that VF-Ag-MOF had the highest catalytic activity, followed by VF-Ag and VF-MOF. The conversion percentage of 4-NP to 4-AP was 69%. The catalytic or photocatalytic effects of VF-Ag, VF-MOF, and VF-Ag-MOF on the elimination of methylene blue (MB) dye were investigated. The results demonstrate that VF-Ag-MOF showed high efficiency in removing the MB dye through the reduction (65%) or photodegradation (71%) after 60min. VF-Ag-MOF composites structure-activity relationships represent that doping within silver NPs enhanced the photocatalytic activity of MIL-125-NH2, which could be explained as follows: (i) Due to the formation of a Schottky barrier at the junction between MIL-125-NH2 and Ag NPs, the photogenerated electrons in the conduction band of MIL-125-NH2 were supposed to be quickly transferred to the valence band of the Ag NPs, and subsequently, the electrons were transferred to the conduction band of Ag NPs. This considerable electron transferring process, which is reported as Z scheme heterojunction, can efficiently suppress the recombination of electron/hole pairs in VF-Ag-MIL-125-NH2 composites. (ii) Sufficient separation between the photogenerated charge carriers (holes and electrons) and avoiding their recombination enhanced the photocatalytic activity of composites.

Adsorptive removal of heavy metal ions from model aqueous media using titanium metal-organic framework and its polyvinyl chloride functionalized composite

The present study was conducted on Ti-MOF and its PVC functionalized composite with the objective of toxic heavy metal ions removal from aqueous media. For achieving this purpose, the solvothermal method was used to synthesis Ti-MOF which was then functionalized with PVC for composite synthesis. The synthesized adsorbent materials were then analyzed via different techniques that include the FTIR, XRD, SEM and EDX analysis along with TGA and point of zero charge (PZC). Batch experiments were conducted for nickel (Ni) and copper (Cu) metal ions sorption from water, using the synthesized adsorbents, under different experimental conditions like initial metal ions concentration, pH, adsorbent’s dosage, time of contact and temperature. The sorption of heavy metal ions by the adsorbents was increased with increasing the media dosage and concentration. Whereas, increasing the pH of the system, from pH-2 to pH-10, also enhanced the sorption phenomenon, because of the pronounced forces of attraction between the positively charged adsorbate ions and the adsorbent’s negatively charged surface, accompanied by precipitation at a much higher pH. It was observed that the adsorption on the functionalized adsorbent surface was greater than the parent MOF material because of the availability of a greater number of adsorption sites, increasing the adsorption capacity of Ni ions from 6.436 to 29.2 mg/g and that of Cu ions from 21.414 to 41.616 mg/g. In addition, the composite material was found to have greater affinity towards Cu metal ions as compared to Ni metal ions, which is attributed to the smaller size of Cu metal ions as compared to Ni ions. To determine the adsorption mechanism, various adsorption isotherms were examined. The results concluded that the Langmuir adsorption isotherm was the suitable model to explain the adsorption mechanism.Moreover, thermodynamic parameters like Gibbs free energy (, change in enthalpy, along with the change in entropy, were determined. The sorption process was found to be more spontaneous at lower temperatures, with the exothermic nature of adsorption, in the case of Ni metal ions and the endothermic nature in the case of Cu metal ions.Also, the negative value of ΔS in case of Ni ions adsorption accounts for the decreased disorderliness of the system which is also the opposite tothat of Cu ions adsorption onto the surface of Ti-PVC composite.The PVC functionalized Ti-MOF was thus found to be an effective, durable, and environmentally friendly adsorbent, for the sorption of heavy metal ions from wastewater.

A porous and photoactive Ti-MOF based on a novel tetranuclear [Ti2Tb2] cluster.

A robust and porous titanium metal-organic framework (Ti-MOF; LCU-505) has been solvothermally synthesized based on an unprecedented tetranuclear Ti2(μ3-O)2Tb2(μ2-CH3COO)2(H2O)4(OOC-)8 cluster (abbreviated as [Ti2Tb2]) and tritopic 4,4',4''-s-triazine-2,4,6-triyl-tribenzoic acid ligand (H3TATB). LCU-505 shows remarkable water stability and permanent porosity for N2 and CO2 gas adsorption. Moreover, LCU-505 demonstrates n-type semiconductor behavior and good photocatalytic activity in the degradation of organic dyes.

Titanium metal–organic framework-derived nanocrystalline TiO2-supported nitrogen-doped carbon nanostructures as highly efficient antibiotic adsorbents

Metal-organic frameworks (MOFs) are explored extensively as a distinctive precursor for producing porous metal oxide-supported nitrogen-doped carbon nanomaterials. MOF-derived materials can offer tailored porosity, structure, and elemental composition so they are gaining prominence as a new-generation adsorbent for emerging antibiotic contaminant removal in aqueous solutions. In this study, we demonstrate the fabrication of nanocrystalline titanium dioxide-supported nitrogen-doped carbon nanostructures (TiO2@NC) obtained from a titanium metal–organic framework (NH2-MIL-125(Ti)) as a starting precursor. When applied as an adsorbent, TiO2@NC nanospheres efficiently removed high concentrations of tetracycline (TC) in aqueous solutions. The TiO2@NC adsorption process obeyed the Langmuir model and pseudo-second-order kinetics. The optimum adsorption capacity of the TiO2@NC nanospheres is estimated to be 1187.08 mg g−1, which is remarkably superior to several previously reported adsorbents for TC removal. The TiO2@NC adsorbent performs efficiently in a broad pH range (3–8) and shows excellent stability. The post-adsorption characterization signifies the crucial role of the adsorbent's nitrogen sites, surface area, and porous sphere morphology in achieving efficient TC removal through hydrogen bonding, π-π interactions, and surface complexation.

Efficient formic acid dehydrogenation on AuPd/N-TiO2: The role of N dopant and the effect of TiO2 crystalline phase

Nitrogen-doped TiO2 (N-TiO2) was prepared by direct pyrolysis of the amino-functionalized titanium metal–organic framework NH2-MIL-125(Ti) in air, and highly dispersed AuPd nanoparticles were anchored on N-TiO2. The synthesized catalysts showed excellent activity for formic acid dehydrogenation. At 60 °C, the total turnover frequency value of Au2Pd8/N-TiO2-catalyzed dehydrogenation reaction was 7725 h−1, which was 2.9 times that of the N-free catalyst (Au2Pd8/TiO2) under the same conditions. The excellent performance of the Au2Pd8/N-TiO2 catalyst was attributed to the high content of anatase TiO2, the synergistic effect between the N-TiO2 support and the metal nanoparticles, the alloying effect between Au and Pd and the small size of the metal particles. The presence of N can enhance the interaction between AuPd and the support, effectively prevent the aggregation of AuPd on the surface of the support, and improve the catalytic activity and reusability of the catalyst. The effect of TiO2 crystalline phase (anatase and rutile) and N doping on the performance of Au2Pd8/N-TiO2-catalyzed formic acid decomposition was analyzed by means of theoretical calculations. The results showed that the anatase and N-TiO2-based catalysts could reduce the barrier for formic acid dehydrogenation. This work combined experiments with theoretical calculations to provide a new approach to the modification of formic acid dehydrogenation catalysts.

Hydrogel assistant synthesis of new Ti-MOF cross-linked oxidized pectin and chitosan with anti-breast cancer properties

Breast cancer is one of the most common diseases of the modern age. Although many methods for its treatment have been reported so far, the report and synthesis of new compounds based on new technologies, especially nanotechnology, is important. One of the laboratory methods for evaluating the anticancer properties of compounds is the in vitro MTT method (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide). In this study, the in vitro anti-breast cancer activity of the newly synthesized (Titanium Metal-Organic Framework) Ti-MOF cross-linked oxidized pectin and chitosan hydrogel, which uses biopolymers in its synthesis and structure, was investigated. The anticancer activity results showed that the synthetic nanopolymer had cell proliferation and viability of 27% more than the control and (the half maximal inhibitory concentration) IC50 of 111 μg/mL against breast cancer cells. Before the anticancer evaluation, the structure of the synthesized Ti-MOF cross-linked oxidized pectin, and chitosan hydrogel was confirmed by (X-Ray Diffraction) XRD pattern (Fourier Transform Infrared) FT-IR spectrum (Energy-dispersive X-ray) EDAX spectroscopy, N2 adsorption/desorption isotherm and (Scanning Electron Microscope) Scanning Electron Microscope images. The results of identification and characterization showed that the synthetic nanopolymer was in the range of nanoparticles. The peaks of the expected functional groups and reactant elements were observed in the FT-IR spectrum and energy-dispersive X-ray spectroscopy of the final product. High physicochemical capabilities such as the uniform morphology, crystallization of particles, and high specific surface area from synthesized Ti-MOF cross-linked oxidized pectin, and chitosan hydrogel were observed. The unique properties of the synthesized Ti-MOF cross-linked oxidized pectin and chitosan hydrogel can be attributed to the appropriate method of its synthesis that was carried out in this study.

TiO2 embedded in ultrathin N-doping carbon nanosheets derived from shape-engineered titanium metal-organic frameworks for lithium-ion storage

The utility of TiO2 as an anode for lithium-ion storage is hindered by low conductivity and sluggish ionic diffusion. Here, the 2D N-doped carbon-wrapped TiO2 (TiO2 @NC) composite with a thickness of 5.5 nm derived from the 2D metal-organic framework was designed. This composite consisting of TiO2 nanoparticles embedded in ultrathin N-doping carbon was used to address the rate and cyclability of Li-ion batteries. The 2D nanosheet morphology obtained from Ti8O8(OH)4(BDC-NH2)6（NH2-MIL-125 (Ti)）effectively increases the specific surface area and shortens the electron/ion transport pathway. The chemical bond of Ti-C-O between TiO2 nanocrystals and N-doping carbon further improve conductivity. Due to its unique structure, the produced TiO2 @NC composite shows excellent cyclability with a reversible capacity of 110 mAh g–1 after 2000 cycles at 0.5 A g–1. Furthermore, the 2D TiO2 @NC exhibits outstanding rate performance (71 mAh g–1 at 5 A g–1) compared to bulk TiO2 @NC. This general concept can be extended to the development of metal oxide materials based on insertion mechanisms, such as Nb2O5.

Titanium metal organic framework based electrocatalytic membrane for fast antibiotics removal: Synergy of defects and hierarchical pore

The spread of antibiotics became a serious risk to human health during wastewater reclamation. Herein, a novel electrocatalytic membrane (ECM) was constructed by facile incorporation of titanium metal organic frameworks (Ti-MOFs) with tunable defect and pore structure into polyvinylidene fluoride (PVDF) membrane for antibiotics removal under electro-assistance. The results showed Ti-MOFs with moderate missing-linker defects and hierarchical pores (Ti-MOFs-1) imparted the membrane with much higher water flux (618.6 L·m−2·h−1·bar−1), oxygen evolution potential (2.16 V), electrochemically active surface area (0.0306 cm2), and lower charge-transfer resistance compared to defect-free Ti-MOFs, thereby rendering higher electrocatalytic activity, increasing tetracycline (TC) removal by more than 40% and reducing the toxicities of intermediates. Interestingly, ECM presented a volcano-type trend in TC removal with the gradual increase of defects and pore size in Ti-MOFs due to the synergistic effect of moderately exposed active sites for generation of •OH and •O2– and hierarchical pore feature for accelerated mass transfer of antibiotics toward the catalytic sites. In addition, the application of ECM in reclamation of simulated municipal wastewater was evaluated. The efficient antibiotics removal efficiency (100%), electrically-driven self-cleaning ability (flux recovery = 100%) and electrochemical stability with low residence time (50.2 s) and energy consumption (0.533 W•h/m3) verify its potential in antibiotics removal.

Metal organic framework as a matrix for laser desorption/ionisation of environmental pollutants and other small molecules

ABSTRACT Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a widely used method for analysing environmental pollutants and proteins. However, this technology has been limited in its ability to analyse small molecules (<700 Da) due to interference from conventional organic matrix background ions, leading to poor signal-to-noise ratios and reproducibility. In an effort to address this limitation, we have developed a new method for synthesising titanium metal organic frameworks (MOFs) as matrices for MALDI-TOF analysis. Specifically, we used a microwave-assisted facile synthesis method that results in smaller MOF particle sizes and requires less reaction time and simpler procedures. Our MOF, also known as NTU-9, was constructed using 2,5-dihydroxybenzoic acid as a ligand and titanium as a metal site. These constituents make NTU-9 highly efficient for photon absorption and target ionisation, allowing for improved MALDI-TOF analysis of diverse molecules, including environmental pollutants and other small molecules.

Enhanced Hg(II) efficient and selective removal by post-functional Ti-MOF with 2，5 thiophene dicarboxylic acid

Toxic mercury ions in wastewater from industrial activities can wreak havoc on the natural environment and ecosystems. Adsorption treatment has been proved to be an effective measure to reduce mercury load in wastewater, but conventional adsorbents have lower adsorption performance. In this study, titanium-metal organic framework (Ti-MOF) was synthesized by solvothermal method, and then further modified by 2,5-thiophene dicarboxylic acid. In order to explore the morphology of the resulting material (OB-MIL-125 (Ti)) and the differences before and after modification, different characterization instruments have been employed. Meanwhile, the properties of materials at different pH were explored, and the adsorption capacity was deeply studied through thermodynamics, kinetics, and adsorption isotherms. The surface of OB-MIL-125 (Ti) had a rich pore structure, so the specific surface area is large, reaching 328.7 m2/g. At room temperature and pH= 5, the maximum removal rate of a 100 ppm solution reached 93.66%. The actual measured maximum adsorption capacity was 1435.98 mg/g. According to isotherm, kinetic and thermodynamic analysis, the process of removing Hg2+ was a multi-layer heterogeneous process, relying on chemical action for adsorption, and it was also a spontaneous exothermic process. The adsorbent presented excellent affinity for mercury and good regeneration ability. To sum up, the OB-MIL-125 (Ti) has great potential for remediation mercury-containing wastewater.

Highly responsive and selective NO2 gas sensors based on titanium metal organic framework (Ti-MOF) with pyromellitic acid

Highly responsive and selective NO2 gas sensors based on titanium metal organic framework (Ti-MOF) with pyromellitic acid

Development of composite optical waveguide based on azobenzene-modified titanium metal-organic framework film for study of gas adsorption kinetics.

This study investigates the fabrication and gas adsorption kinetics of an azobenzene (AZB)-modified titanium metal-organic framework (AZB@Ti-MOF) film composite optical waveguide (COWG) that recognizes ethylenediamine (EDA) gas. After modification with AZB, the surface of the Ti-MOF film became rough and evolved from a hemispherical structure to a petal-like structure; a large pore size and small specific surface area accompanied the evolution of the surface morphology. The AZB@Ti-MOF film COWG exhibited a positive response to EDA gas co-existing with the same concentration (1000 ppm) of benzenes, amines, and acidic gases. It is postulated that charge transfer occurs when the AZB@Ti-MOF film COWG adsorbs EDA gas, leading to significant strengthening of the intramolecular hydrogen bonds as EDA works as an electron donor. Incomplete or prolonged EDA desorption from the film surface at room temperature resulted in a decrease in the surface sensitivity of the COWG AZB@Ti-MOF film. The kinetics of EDA adsorption were examined using pseudo-first-order and pseudo-second-order (PSO) kinetic models. The EDA adsorption kinetics fit well with the PSO model. As measured at room temperature, the adsorption capacity (qe) per unit surface of the AZB@Ti-MOF films was 46.50 × 10-2 µg·cm-2.

A robust and porous titanium metal-organic framework for gas adsorption, CO2 capture and conversion.

A robust and porous titanium metal-organic framework (Ti-MOF; LCU-402) has been hydrothermally synthesized through combining a tetranuclear Ti2Ca2(μ3-O)2(μ2-H2O)1.3(H2O)4(O2C-)8 cluster and a tritopic 1,3,5-benzene(tris)benzoic (BTB) ligand. LCU-402 shows remarkable stability and permanent porosity for CO2, CH4, C2H2, C2H4, and C2H6 gas adsorption. Moreover, LCU-402 as a heterogeneous catalyst can smoothly convert CO2 under a simulated flue atmosphere into organic carbonate molecules by cycloaddition reactions of CO2 and epoxides, indicating that LCU-402 might be a promising catalyst candidate in practical applications. We are confident that the identification of a persistent titanium-oxo building unit would accelerate the development of new porous Ti-MOF materials.

Hierarchical Ti-MOF Microflowers for Synchronous Removal and Fluorescent Detection of Aluminum Ions.

Bifunctional luminescence metal-organic frameworks with unique nanostructures have drawn ongoing attention for simultaneous determination and elimination of metal ions in the aqueous environment, but still remain a great challenge. In this work, three-dimensional hierarchical titanium metal-organic framework (Ti-MOF) microflowers were developed by a secondary hydrothermal method for not only highly sensitive and selective detection of Al(III), but also simultaneously efficient decontamination. The resulting Ti-MOF microflowers with a diameter of 5-6 μm consisted of nanorods with a diameter of ∼200 nm and a length of 1-2 μm, which provide abundant, surface active sites for determination and elimination of Al(III) ions. Because of their substantial specific surface area and superior fluorescence characteristics, Ti-MOF microflowers are used as fluorescence probes for quantitative determination of Al(III) in the aqueous environment. Importantly, the specific FL enhancement by Al(III) via a chelation-enhanced fluorescence mechanism can be utilized for selective and quantitative determination of Al(III). The Al(III) detection has a linear range of 0.4-15 µM and a detection limit as low as 75 nM. By introducing ascorbic acid, interference of Fe(III) can be avoided to achieve selective detection of Al(III) under various co-existing cations. It is noteworthy that the Ti-MOF microflowers exhibit excellent adsorption capacity for Al(III) with a high adsorption capacity of 25.85 mg g-1. The rapid adsorption rate is consistent with a pseudo-second order kinetic model. Ti-MOF is a promising contender as an adsorbent and a fluorescent chemical sensor for simultaneous determination and elimination of Al(III) due to its exceptional water stability, high porosity, and intense luminescence.

Photocatalytic reduction of chromium by titanium metal organic frameworks in the presence of low-molecular-weight organic acids under UV and visible light

The LMWOAs have an α-hydroxy group and dissociate into R-COO.- radicals and electrons. These electrons, along with electrons from the conduction band of photocatalysts, transfer to Cr (VI), reduce it to Cr (III). Here, we explore this phenomenon of under ultraviolet (UV) and visible light, using MIL-125(Ti) and solvothermally modified RG-MIL as photocatalysts, respectively. Tartaric acid (TA) exhibits a greater reduction potential under both UV and visible light. The reduction of chromium increases 1.27-fold and 1.68-fold under UV and visible light, respectively. A maximum reduction efficiency was evident at a pH of 2 and a TA dose of 1 mmol/L for both UV and visible light. Changes in the molecular fingerprints of a photocatalyst after chromium reduction were investigated through Fourier-transform infrared analysis. Negligible changes were observed before and after the reaction, indicating that the structure of the photocatalyst remained largely intact. Mechanism studies show the development of a charge-transfer complex between the photocatalyst and LMWOA. Electrons transfer from the photocatalyst into the chromium, resulting in enhancement of chromium reduction potential. Quantitative investigations of the reduction performance of both systems indicate that MIL-125(Ti) + TA and RGO-MIL + TA are as effective as systems reported previously in the literature.

Screen-printed electrode modified by Au/NH2-MIL-125(Ti) composite for electrochemical sensing performance of gallic acid in green tea and urine samples

Gold (Au) nanoparticles decorated titanium-metal-organic framework (Ti-MOF) composite was synthesized for electrochemical detection of gallic acid (GA). Morphological analysis showed that the Au nanoparticles with an average size of < 10 nm were dispersed on the Ti-MOF. Cyclic voltammetric analysis showed that the screen-printed electrode (SPE) modified by Au/Ti-MOF composite showed redox peaks with higher currents. The Au/Ti-MOF/SPE exhibited a linear range and sensitivity of 0.01–100 µM and 0.77 µM/µA, respectively. The Au/Ti-MOF/SPE showed a very low response for the interference materials. The real sample analysis revealed that the Au/Ti-MOF/SPE exhibited good recovery towards the GA in green tea and human urine.

Construction of covalent-integrated MOFs@COFs composite material for efficient synergistic adsorption and degradation of pollutants

Titanium metal–organic frameworks (Ti-MOFs) are very attractive artificial photocatalysts for their good photo-redox activity. However, due to the poor visible light responsiveness of Ti-MOFs, the solar energy conversion efficiency is greatly limited. Herein, this paper adopts a covalent-integrated strategy to combine Ti-MOFs and covalent organic frameworks (COFs) with triazine frameworks through covalent bonding to construct MOFs@COFs Z-scheme heterojunction composite material. This material broadens the visible light response range and has suitable band gap and more active sites. It is noteworthy that composite material exhibits high synergistic adsorption and degradation performance for photocatalytic high concentration of bisphenol A (BPA). Thanks to the efficient photo-generating electron and hole transport, NM-125(Ti)0.4@TpTta-COF achieves synergistic adsorption and degradation of 100 ppm BPA within 10 mins, which is more efficient than other materials. Furthermore, this material exhibits high stability and universality, which provides a feasible strategy for designing and synthesizing photocatalytic materials with high light response.

Electrochemical aptasensing strategy based on a multivariate polymertitanium-metal-organic framework for zearalenone analysis

An electrochemical aptasensing strategy was developed with a novel bioplatform based on a multivariate titanium metal–organic framework, i.e. MTV polyMOF(Ti), to detect zearalenone (ZEN). MTV polyMOF(Ti) was prepared by using mixed linkers of polyether polymer (pbdc-xa or L8, pbdc = poly(1,4-benzenedicarboxylate) and 1,4-benzenedicarboxylic acid (H2bdc or L0) as well as tetrabutyl titanate as nodes (MTV polyMOF(Ti)-L8,0). Compared with Ti-MOFs synthesized by using the single ligand of L8 or L0, MTV polyMOF(Ti)-L8,0 shows more porous structure assembled with multilayered nanosheets. In light of the improved electrochemical activity and strong bioaffinity to the aptamer, the aptasensor based on MTV polyMOF(Ti)-L8,0 shows excellent performance for detecting ZEN with the ultralow detection limit at fg mL−1 level in the linear range of 10 fg mL−1 to 10 ng mL−1, along with good selectivity, reproducibility, stability, regenerability, and applicability.

Stable titanium metal-organic framework with strong binding affinity for ethane removal

Abstract Direct separation of high purity ethylene (C2H4) from an ethane (C2H6)/ethylene mixture is a critical and challenging task owing to the very similar molecular size and physical properties of the two components. While some studies have attempted this separation, there is a lack of excellent porous materials with strong binding affinity for C2H6-selective adsorption via an energy-efficient adsorptive separation process. Herein, we report a titanium metal-organic framework with strong binding affinity and excellent stability for the highly efficient removal of C2H6 from C2H6/C2H4 mixtures. Single component adsorption isotherms demonstrated a larger amount of adsorbed ethane (1.16 mmol·g−1 under 1 kPa) and high C2H6/C2H4 selectivity (2.7) for equimolar C2H6/C2H4 mixtures, especially in the low-pressure range, which is further confirmed by the results of grand canonical Monte Carlo simulations for C2H6 adsorption in this framework. The experimental breakthrough curves showed that C2H4 with a high purity was collected directly from both 1:9 and 1:15 C2H6/C2H4 (volume ratio) mixtures at 298 K and 100 kPa. Moreover, the unchanged adsorption and separation performance after cycling experiments confirmed the promising applicability of this material in future.