scholarly journals Unravelling surface and interfacial structures of a metal–organic framework by transmission electron microscopy

2017 ◽  
Vol 16 (5) ◽  
pp. 532-536 ◽  
Author(s):  
Yihan Zhu ◽  
Jim Ciston ◽  
Bin Zheng ◽  
Xiaohe Miao ◽  
Cory Czarnik ◽  
...  
2016 ◽  
Vol 70 (5) ◽  
pp. 565-572 ◽  
Author(s):  
Remy Vala ◽  
Donbebe Wankasi ◽  
Ezekiel Dikio

In this paper, we report the synthesis of metal organic framework of uranium 1,2,4,5-benzene tetracarboxylic acid (U-H4btec MOF) by solvothermal method. The obtained MOF was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), Energy dispersive spectroscopy (EDS), thermogravimetric and differential thermogravimetric analysis (TGA/DTA). The morphology of the uranium 1,2,4,5-benzene tetracarboxylic acid MOF observed by SEM, revealed the presence of flaky porous structure. Adsorption of Cr3+ from aqueous solution onto the uranium 1,2,4,5-benzene tetracarboxylic acid MOF was systematically studied. Langmuir and Freundlich adsorption isotherms were applied to determine the adsorption capacity of the MOF to form a monolayer. Kinetic determination of the adsorption of Cr3+ suggested both chemisorption and physisorption probably due to the presence of carbonyl groups within the MOF and its porous structure.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Son Doan Hoai ◽  
Tram Van Thi ◽  
Giao Dang Huynh ◽  
Nhan Le Thi Hong ◽  
Nam Phan Thanh Son

A porous crytalline metal-organic framework Fe3O(BPDC)3 was synthesized, and its properties were characterized by various techniques, including X-ray powder diffraction (PXRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen physisorption measurements. The Fe3O(BPDC)3 was used as an efficient catalyst for the oxidative coupling reaction of benzaldehyde and (E)-1-phenylethan-1-one O-acetyl oxime to form 2,4,6-triphenylpyridine as desired product. The reaction could proceed readily, with more than 83 % reaction yield being achieved after 360 min at 140 oC in the presence of 10 mol% Fe3O(BPDC)3) catalyst and Di-tert-butyl peroxide as an oxidant. This Fe-MOF exhibited higher activity than other MOFs and traditional homogeneous catalysts in the oxidative coupling reaction. The transformation could only proceed to obtain main product in the presence of Fe3O(BPDC)3.


2019 ◽  
Vol 9 (22) ◽  
pp. 4952 ◽  
Author(s):  
Sushma Rani ◽  
Bharti Sharma ◽  
Shivani Kapoor ◽  
Rajesh Malhotra ◽  
Rajender S. Varma ◽  
...  

In the present study, we report a highly effective electrochemical sensor for detecting 2,4-dinitrotoluene (2,4-DNT). The amperometric determination of 2,4-DNT was carried out using a gold electrode modified with zinc–metal organic framework-8 and silver quantum dot (Zn-MOF-8@AgQDs) composite. The synthesized nanomaterials were characterized by using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The synthesized nanocomposite proved to be efficient in electro-catalysis thereby reducing the 2,4-DNT. The unique combination present in Zn-MOF-8@AgQDs composite offered an excellent conductivity and large surface area enabling the fabrication of a highly sensitive (−0.238 µA µM−1 cm−2), selective, rapid and stable 2,4-DNT sensor. The dynamic linear range and limit of detection (LOD) was about 0.0002 µM to 0.9 µM and 0.041 µM, respectively. A 2,4-DNT reduction was also observed during the linear sweep voltammetry (LSV) experiments with reduction peaks at −0.49 V and −0.68 V. This is an unprecedented report with metal organic framework (MOF) composite for sensing 2,4-DNT. In addition, the presence of other species such as thiourea, urea, ammonia, glucose, and ascorbic acid displayed no interference in the modified electrode suggesting its practicability in various environmental applications.


2021 ◽  
Vol 9 ◽  
Author(s):  
Malihe Zeraati ◽  
Abbas Rahdar ◽  
Dora I. Medina ◽  
Ghasem Sargazi

In this study, novel nanostructures of aluminum base metal-organic framework (Al-MOF) samples were synthesized using a sustainable, non-toxic, and cost-effective green synthesis route. Satureja hortensis extract was used as an effective source of linker for the development of the Al-MOF structures. The Fourier-transformed infrared (FTIR) spectrum confirmed the presence of characterization bonds related to the Al-MOF nanostructures synthesized by the green synthesis route. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed that the sample synthesized by Na2-CA was composed of multilayers, although it was agglomerated, but it had dispersed and occurred in spherical particles, indicating active organic matter. N2 adsorption/desorption isotherms demonstrated the significant porosity of the Al-MOF samples that facilitate the high potential of these nanostructures in medical applications. The anticancer treatment of Al-MOF samples was performed with different concentrations using the MTT standard method with untreated cancer cells for 24 and 48 h periods. The results exhibited the significant anticancer properties of Al-MOF samples developed in this study when compared with other MOF samples. Thus, the development of a novel Al-MOF and its application as a natural linker can influence the anticancer treatment of the samples. According to the results, the products developed in this study can be used in more applications such as biosensors, catalysts, and novel adsorbents.


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