Combining the physical advantages of two-dimensional (2D) inorganic nanosheets and the modular design and programmed structure of metal-organic frameworks (MOFs), 2D MOFs remain at the forefront of functional material research. Despite tremendous efforts, precise control in the synthesis of 2D nonlayered MOFs with predesigned topology for desired applications remains challenging. Success in the bottom-up synthesis of 2D nonlayered MOFs via ligand exchange motivated us to incorporate partial BTC (BTC = 1,3,5-benzenetricarboxylate) ligand dissociation and CO2 capped coordination into the top-down treatment of bulk Cu-BTC MOF, leading to successful conversion of a 3D nonlayered network to a 2D Cu-based topological structure. Notably, a supercritical CO2-containing solvent mixture is employed to provide the desired defect and coordination engineering. Thus, our work introduces a new top-down concept based on modulated synthesis to fabricate high-quality 2D nonlayered MOFs for the first time.

Metal-organic framework (MOF) films can be used in various applications. In this work, we propose a method that can be used to synthesize MOF films localized on a single side of an anion exchange membrane, preventing the transport of the metal precursor via Donnan exclusion. This is advantageous compared to the related contra-diffusion method that results in the growth of a MOF film on both sides of the support, differing in quality on both sides. Our proposed method has the advantage that the synthesis conditions can potentially be tuned to create the optimal conditions for crystal growth on a single side. The localized growth of the MOF is governed by Donnan exclusion of the anion exchange membrane, preventing metal ions from passing to the other compartment, and this leads to a local control of the precursor stoichiometry. In this work, we show that our method can localize the growth of both Cu-BTC and ZIF-8 in water and in methanol, respectively, highlighting that this method can used for preparing a variety of MOF films with varying characteristics using soluble precursors at room temperature.

In this paper, Cu-BTC derived mesoporous CuS nanomaterial (m-CuS) was synthesized via a two-step process involving carbonization and sulfidation of Cu-BTC for colorimetric glutathione detection. The Cu-BTC was constructed by 1,3,5-benzenetri-carboxylic acid (H3BTC) and Cu2+ ions. The obtained m-CuS showed a large specific surface area (55.751 m2/g), pore volume (0.153 cm3/g), and pore diameter (15.380 nm). In addition, the synthesized m-CuS exhibited high peroxidase-like activity and could catalyze oxidation of the colorless substrate 3,3\',5,5\'-tetramethylbenzidine to a blue product. Peroxidase-like activity mechanism studies using terephthalic acid as a fluorescent probe proved that m-CuS assists H2O2 decomposition to reactive oxygen species, which are responsible for TMB oxidation. However, the catalytic activity of m-CuS for the oxidation of TMB by H2O2 could be potently inhibited in the presence of glutathione. Based on this phenomenon, the colorimetric detection of glutathione was demonstrated with good selectivity and high sensitivity. The linear range was 1-20 μM and 20-300 μM with a detection limit of 0.1 μM. The m-CuS showing good stability and robust peroxidase catalytic activity was applied for the detection of glutathione in human urine samples.

Adsorptive removal of dyes (e.g., malachite green (MG)) from wastewater using commercially available adsorbents is not significantly efficient. Metal-organic frameworks (MOFs) such as Cu-BTC is considered as an excellent adsorbent in adsorption-separation filed. However, the water instability of Cu-BTC restricts its potential utilization in dye wastewater purification. In this paper, we have developed a novel metal/covalent-organic frameworks (Cu-BTC@TpPa-1) binary composite by solvothermal method. This composite serves as a multifunctional platform for the effective removal of MG from water. This Cu-BTC@TpPa-1 obviously keeps structural integrity soaked in water for 7 days. And its heat resistant performance can achieve 360 °C because of the TpPa-1 protection, which is outdistance to that of Cu-BTC. The adsorbed capacity of MG over Cu-BTC@TpPa-1 is exceptionally high, with an uptake of up to 64.12 mg/g, which is superior compared to previous adsorbents, highlighting its superior adsorption capabilities. The adsorptive performance was controlled by the associative effects of Cu-BTC and TpPa-1 with an association effect of π-complexation and electrostatic attraction. The Cu-BTC@TpPa-1 might be a prospective adsorbent for MG capture from industrial wastewater.

Erythromycin, a commonly used macrolide antibiotic, plays a crucial role in both human medicine and animal husbandry. However, its abuse has led to residual presence in the environment, with problems such as the emergence of resistant bacteria and enrichment of resistance genes. These issues pose significant risks to human health. Thus far, there are no effective, environmentally friendly methods to manage this problem. Enzymes can specifically degrade erythromycin without causing other problems, but their unrecyclability and environmental vulnerability hinder large-scale application. Enzyme immobilization may help to solve these problems. This study used Cu-BTC, a synthetic metal-organic framework, to immobilize the erythromycin-degrading enzyme EreB. The loading temperature and enzyme quantity were optimized. The Cu-BTC and EreB@Cu-BTC were characterized by various methods to confirm the preparation of Cu-BTC and immobilization of EreB. The maximum enzyme loading capacity was 66.5 mg g-1. In terms of enzymatic properties, immobilized EreB had improved heat (25-45 °C) and alkaline (6.5-10) tolerance, along with greater affinity between the enzyme and its substrate; Km decreased from 438.49 to 372.30 mM. Recycling was also achieved; after 10 cycles, 57.12% of the enzyme activity was maintained. After composite degradation, the antibacterial activity of erythromycin-containing wastewater was examined; the results showed that the novel composite could completely inactivate erythromycin. In summary, Cu-BTC was an ideal carrier for immobilization of the enzyme EreB, and the EreB@Cu-BTC composite has good prospects for the treatment of erythromycin-containing wastewater.

The recovery of organophosphate pesticides (OPPs) from aqueous solutions is imperative considering their agricultural and environmental implications. Among various mitigation approaches used for OPPs\' removal, adsorption offers many advantageous features for OPPs abatement owing to its benign nature, cost-effective processing, and non-requirement of excessive equipment. This research describes the adsorptive removal of three organophosphate pesticides (OPPs) namely chlorpyrifos (CPF), methyl parathion (MP), and malathion (MAL) by HKUST-1 (HKUST = Hong Kong University of Science and Technology) metal-organic framework (MOF). The synthesis of HKUST-1 MOFs was confirmed by various spectroscopic and microscopic techniques. The adsorption kinetics was systematically investigated by varying three parameters to include solution pH, contact time, and initial pesticide concentration. Among all the three pesticides, HKUST-1 showed enhanced removal of CPF in terms of pH, resulting in an adsorption capacity of 1.82 mg·g-1. However, under the effect of contact time at 60 min, the adsorption capacity of HKUST-1 for PM, MAL, and CPF were computed to be 1.83, 1.79, and 0.44 mg·g-1, respectively. Besides, HKUST-1 showed a remarkable performance towards adsorptive removal of MAL (14.01 mg·g-1 at 10 mg·L-1 concentration) with linear increase in adsorption capacity as the function of initial pesticide concentration. The MOFs were also able to retain ca. 50% of their adsorption efficiency over the course of five cycles of adsorptive removal of CP. In the future, a comprehensive data table showing the performance of various MOFs against various OPPs can be constructed on the basis of parameters used in this study.

With the growing population, industrialization, and agriculture, water contamination not only affects people but entire ecosystems. Metal-organic frameworks (MOFs), because of their large surface area and porosity, show great potential as adsorbents for removing pollutants, such as heavy metals, from contaminated water. The current research aims at examining copper (II) benzene-1,3,5-tricarboxylate (Cu-BTC) MOFs and understanding the mechanism for their adsorption of Pb(II) from aqueous solution. The Cu-BTC samples were characterized using FTIR and XRD, and their surface area and porosity were determined based on N2 adsorption isotherms. The concentration of Pb(II) in the solutions was measured using atomic absorption spectroscopy (AAS). Both kinetic and equilibrium adsorption data were collected and then analyzed using numerical models. The analyses led to the findings that the limiting steps in the adsorption of Pb(II) on Cu-BTC are (a) pore diffusion of Pb(II) and (b) the availability of the active sites on Cu-BTC MOFs. It was further revealed that the former step is more dominant in the adsorption of Pb(II) when the lead concentration is low. The latter step, which is directly proportional to the surface areas of the MOFs, affects the adsorption to a greater extent when the lead concentration is high. The results also show that adsorption of Pb(II) ions on Cu-BTC is mainly a multi-layer heterogeneous process.

Two-dimensional (2D) nanomaterials can improve drug delivery by reducing toxicity, increasing bioavailability and boosting efficacy. In this study, the simultaneous use of transition metal carbides and nitrides (MXenes) along with copper (II) benzene-1, 3, 5-tricarboxylate metal-organic framework (Cu - BTC/MOF) as attractive nanocarriers are investigated for loading and delivering curcumin (CUR) and paclitaxel (PTX) drugs to cancer cells. The efficiency of surface termination (bare and oxygen) in the adsorption of PTX and CUR drugs and the co-loading of these two drugs are evaluated. Our results show that the strongest interaction energy belongs to the adsorption of drug CUR on the MXNNO-Cu-BTC adsorbent, while the interaction of PTX drug with the MXNO- Cu-BTC in the MXNO-Cu-BTC/PTX&CUR system is the lowest due to the particular structure of the drug and the adsorbent. Our results show that at the beginning simulation, the interaction energy between the PTX drug and water in PTX/MXN system is -4645.48 kJ/mol, which reduces to -3848.71 kJ/mol after the system reaches equilibrium. Therefore, the inspected adsorbents have a good performance in adsorbing CUR and PTX drugs. The obtained results from this investigation provide valuable information about experimental studies by medical scientists in the future.Communicated by Ramaswamy H. Sarma.

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.

Gas-phase infiltration of the carbonylchloridogold(I), Au(CO)Cl precursor into the pores of HKUST-1 ([Cu3(BTC)2(H2O)2], Cu-BTC) SURMOFs (surface-mounted metal-organic frameworks; BTC = benzene-1,3,5-tricarboxylate) leads to Au(CO)Cl decomposition within the MOF through hydrolysis with the aqua ligands on Cu. Small Aux clusters with an average atom number of x ≈ 5 are formed in the medium-sized pores of the HKUST-1 matrix. These gold nanoclusters are homogeneously distributed and crystallographically ordered, which was supported by simulations of the powder X-ray diffractometric characterization. Aux@HKUST-1 was further characterized by scanning electron microscopy (SEM) and infrared reflection absorption (IRRA) as well as Raman spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectroscopy (ICP-OES).