An In-Situ-Grown Cu-BTC Metal–Organic Framework / Graphene Oxide Hybrid Adsorbent for Selective Hydrogen Storage at Ambient Temperature

Encapsulation of Candida antarctica lipase B in metal-organic framework under ultrasound and using it to one-pot synthesis of 1,3,4,5-tetrasubstituted pyrazoles

Encapsulating the enzyme in metal-organic frameworks (MOFs) is a convenient method to prepare MOF-enzyme biocomposite. In this study, Candida antarctica lipase B (CAL-B) was chosen to immobilize in Cu-BTC MOF under ultrasound irradiation. CAL-B was immobilized in Cu-BTC under ultrasound at 21 kHz and 11.4 W/cm2 and incubation. 98% of CAL-B was immobilized in Cu-BTC with 99 U/mg activity (threefold more active than the free CAL-B). The prepared biocomposite was characterized using FT-IR, XRD, TGA, SEM, EDX, and BET. The thermal and solvent stability of CAL-B@Cu-BTC was investigated. It was found that at a temperature of 55 ℃, CAL-B@Cu-BTC maintains its activity even after 2 h of incubation. Furthermore, in the presence of 20% and 50% concentrations of MeCN, THF, and DMF, CAL-B@Cu-BTC was found to have an activity of over 80%. A prepared biocatalyst was used to synthesize 1,3,4,5-tetrasubstituted pyrazole derivatives (50-75%) in a one-pot vessel, by adding phenyl hydrazine hydrochlorides, benzaldehydes, and dimethyl acetylenedicarboxylate.

Hierarchically Porous Structured Adsorbents with Ultrahigh Metal-Organic Framework Loading for CO2 Capture

Metal-organic frameworks (MOFs) have emerged as promising candidates for CO2 adsorption due to their ultrahigh-specific surface area and highly tunable pore-surface properties. However, their large-scale application is hindered by processing issues associated with their microcrystalline powder nature, such as dustiness, pressure drop, and poor mass transfer within packed beds. To address these challenges, shaping/structuring micron-sized polycrystalline MOF powders into millimeter-sized structured forms while preserving porosity and functionality represents an effective yet challenging approach. In this study, a facile and versatile strategy was employed to integrate moisture-stable and scalable microcrystalline MOFs (UiO-66 and ZIF-8) into a poly(acrylonitrile) matrix to fabricate readily processable, millimeter-sized hierarchically porous structured adsorbents with ultrahigh MOF loadings (∼90 wt %) for direct industrial carbon capture applications. These structured composite beads retained the physicochemical properties and separation performance of the pristine MOF crystal particles. Structured UiO-66 and ZIF-8 exhibited high specific surface areas of 1130 m2 g-1 and 1431 m2 g-1, respectively. The structured UiO-66 achieved a CO2 adsorption capacity of 2.0 mmol g-1 at 1 bar and a dynamic CO2/N2 selectivity of 17 for a CO2/N2 gas mixture with a 15/85 volume ratio at 25 °C. Furthermore, the structured adsorbents exhibited excellent cyclability in static and dynamic CO2 adsorption studies, making them promising candidates for practical application.

Cu/Cu2O/C nanoparticles and MXene based composite for non-enzymatic glucose sensors

Copper/Cuprous oxide/Carbon nanoparticles decorated MXene composite was prepared and subsequently examined for its potential application as a non-enzymatic glucose sensor. To carry out this, initially the Cu MOF/MXene composite was synthesised by the hydrothermal method and was annealed in an unreacted environment at different time intervals. During this process, petal like Cu MOF on MXene loses the organic ligands to form a Cu/Cu2O/C based nanoparticles on MXene. Further, an electrode was fabricated with the developed material for understanding the sensing performance by cyclic voltammetry and chronoamperometry in 0.1 M NaOH solution. Results reveal that the highest weight percentage of copper oxide in the composite (15 min of annealed material) shows a higher electro catalytic activity for sensing glucose molecules due to more active sites with good electron transfer ability in the composite. The formed composite exhibits a wide linear range of 0.001-26.5 mM, with a sensitivity of 762.53μAmM-1cm-2(0.001-10.1 mM), and 397.18μAmM-1cm-2(11.2-26.9 mM) and the limit of detection was 0.103μM. In addition to this, the prepared electrode shows a good reusability, repeatability, selectivity with other interferences, stability (93.65% after 30 days of storage), and feasibility of measuring glucose in real samples. This finding reveals that the metal oxide derived from MOF based nanoparticle on the MXene surface will promote the use of non-enzymatic glucose sensors.

Bimetallic Copper-Cerium-Based Metal-Organic Frameworks for Selective Carbon Dioxide Capture

Metal-organic frameworks (MOFs) are highly regarded as valuable adsorbent materials in materials science, particularly in the field of CO2 capture. While numerous single-metal-based MOFs have demonstrated exceptional CO2 adsorption capabilities, recent advancements have explored the potential of bimetallic MOFs for enhanced performance. In this study, a CuCe-BTC MOF was synthesized through a straightforward hydrothermal method, and its improved properties, such as high surface area, smaller pore size, and larger pore volume, were compared with those of the bare Ce-BTC. The impact of the Cu/Ce ratio (1:4, 1:2, 1:1, and 3:2) was systematically investigated to understand how adding a second metal influences the CO2 adsorption performance of the Ce-BTC MOF. Various characterization techniques, including scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and N2 BET surface area analysis, were employed to assess the physical and chemical properties of the bare Ce-BTC and CuCe-BTC samples. Notably, CuCe-BTC-1:2 exhibited superior surface area (133 m2 g-1), small pore size (3.3 nm), and large pore volume (0.14 cm3 g-1) compared to the monometallic Ce-BTC. Furthermore, CuCe-BTC-1:2 demonstrated a superior CO2 adsorption capacity (0.74 mmol g-1), long-term stability, and good CO2/N2 selectivity. This research provides valuable insights into the design of metal-BTC frameworks and elucidates how introducing a second metal enhances the properties of the monometallic Ce-BTC-MOF, leading to improved CO2 capture performance.

Cu-BTC Derived Mesoporous CuS Nanomaterial as Nanozyme for Colorimetric Detection of Glutathione

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.

Development of new magnetic nanocomposite designed by reduced graphene oxide aerogel and HKUST-1, and its catalytic application in the synthesis of polyhydroquinoline and 1,8-dioxo-decahydroacridine derivatives

In this study, new magnetic reduced graphene oxide aerogel/HKUST-1 nanocomposite was designed and synthesized given the transformation of graphene oxide sheets to three-dimensional reduced graphene oxide aerogel, the in-situ magnetization of aerogel substrate, and the in-situ formation of HKUST-1 particles. Apart from characterizing the chemistry and structure of the designed magnetic nanocomposite (FT-IR, EDX, ICP, FE-SEM, DLS, XRD, VSM, and TG analyses), its catalytic performance was evaluated in the one-pot synthesis of biologically active 1,8-dioxo-decahydroacridine and polyhydroquinoline derivatives. The combination of magnetized reduced graphene oxide aerogel and HKUST-1 in the form of a new heterogeneous magnetic nanocatalyst was accompanied by a high synergetic catalytic effect in the symmetric and unsymmetrical Hantzsch condensation reactions. Compared to previous research studies, the pharmaceutical 1,8-dioxo-decahydroacridine and polyhydroquinoline derivatives can be synthesized using a partial amount of this nanocatalyst with a high percentage of yields in a short reaction time.

Highly improved pH-Responsive anticancer drug delivery and T2-Weighted MRI imaging by magnetic MOF CuBTC-based nano/microcomposite

Cu-BTC framework has received a considerable attention in recent years as a drug carrier candidate for cancer treatment due to its unique structural properties and promising biocompatibility. However, its intrinsic deficiency for medical imaging potentially limits its bioapplications; To address this subject, a magnetic nano/microscale MOF has been successfully fabricated by introducing Fe₃O₄ nanoparticles as an imaging agent into the porous isoreticular MOF [Cu₃(BTC)₂] as a drug carrier. The synthesized magnetic MOFs exhibits a high loading capacity (40.5%) toward the model anticancer DOX with an excellent pH-responsive drug release. The proposed nanocomposite not only possesses large surface area, high magnetic response, large mesopore volume, high transverse relaxivity (r ²) and good stability but also exhibits superior biocompatibility, specific tumor cellular uptake, and significant cancer cell viability inhibitory effect without any targeting agent. It is expected that the synthesized magnetic nano/microcomposite may be used for clinical purposes and can also serve as a platform for photoactive antibacterial therapy ae well as pH/GSH/photo-triple-responsive nanocarrier.