scholarly journals Detection of Adsorbates on Emissive MOF Surfaces with X-Ray Photoelectron Spectroscopy

2018 ◽  
Author(s):  
Shawn Burdette ◽  
Jingjing Yan ◽  
Ron Grimm ◽  
Peter Mueller ◽  
Alexander Carl ◽  
...  

A metal organic framework containing an azobenzene chromophore exhibits luminescence that is quenched by nitro-phenol derivatives. The model system was used to develop an new analytical approach to differentiating between encapsulated guest molecules and those adsorbed on the outside of the MOF

2018 ◽  
Author(s):  
Shawn Burdette ◽  
Jingjing Yan ◽  
Ron Grimm ◽  
Peter Mueller ◽  
Alexander Carl ◽  
...  

A metal organic framework containing an azobenzene chromophore exhibits luminescence that is quenched by nitro-phenol derivatives. The model system was used to develop an new analytical approach to differentiating between encapsulated guest molecules and those adsorbed on the outside of the MOF


2019 ◽  
Vol 48 (14) ◽  
pp. 4520-4529 ◽  
Author(s):  
Jingjing Yan ◽  
Alexander D. Carl ◽  
Alex R. Maag ◽  
John C. MacDonald ◽  
Peter Müller ◽  
...  

The luminescence of azobenzene chromophore struts in a metal organic framework is quenched by nitroaromatic guests. X-ray photoelectron spectroscopic methods verify the emission changes are due to the surface adsorption of the guest molecules rather than encapsulation.


2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
José María Rivera ◽  
Susana Rincón ◽  
Cherif Ben Youssef ◽  
Alejandro Zepeda

Mesoporous metal-organic framework-5 (MOF-5), with the composition Zn4O(BDC)3, showed a high capacity for the adsorptive removal of Pb(II) from 100% aqueous media. After the adsorption process, changes in both morphology and composition were detected using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) system, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis. The experimental evidence showed that Zn(II) liberation from MOF-5 structure was provoked by the water effect demonstrating that Pb(II) removal is not due to ionic exchange with Zn. A kinetic study showed that Pb(II) removal was carried out in 30 min with a behavior of pseudo-second-order kinetic model. The experimental data on Pb(II) adsorption were adequately fit by both the Langmuir and BET isotherm models with maximum adsorption capacities of 658.5 and 412.7 mg/g, respectively, at pH 5 and 45°C. The results of this work demonstrate that the use of MOF-5 has great potential for applications in environmental protection, especially regarding the removal of the lead present in industrial wastewaters and tap waters.


2019 ◽  
Author(s):  
Luzia S. Germann ◽  
Athanassios D. Katsenis ◽  
Igor Huskić ◽  
Patrick A. Julien ◽  
Krunoslav Uzarevic ◽  
...  

Manuscript about monitoring the mechanochemical reaction of a metal-organic framework model system by in situ X-ray powder diffraction<br>


2019 ◽  
Author(s):  
Luzia S. Germann ◽  
Athanassios D. Katsenis ◽  
Igor Huskić ◽  
Patrick A. Julien ◽  
Krunoslav Uzarevic ◽  
...  

Manuscript about monitoring the mechanochemical reaction of a metal-organic framework model system by in situ X-ray powder diffraction<br>


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Pham Dinh Du ◽  
Huynh Thi Minh Thanh ◽  
Thuy Chau To ◽  
Ho Sy Thang ◽  
Mai Xuan Tinh ◽  
...  

In the present paper, the synthesis of metal-organic framework MIL-101 and its application in the photocatalytic degradation of Remazol Black B (RBB) dye have been demonstrated. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption/desorption isotherms at 77 K. It was found that MIL-101 synthesized under optimal conditions exhibited high crystallinity and specific surface area (3360 m2·g-1). The obtained MIL-101 possessed high stability in water for 14 days and several solvents (benzene, ethanol, and water at boiling temperature). Its catalytic activities were evaluated by measuring the degradation of RBB in an aqueous solution under UV radiation. The findings show that MIL-101 was a heterogeneous photocatalyst in the degradation reaction of RBB. The mechanism of photocatalysis was considered to be achieved by the electron transfer from photoexcited organic ligands to metallic clusters in MIL-101. The kinetics of photocatalytic degradation reaction were analyzed by using the initial rate method and Langmuir-Hinshelwood model. The MIL-101 photocatalyst exhibited excellent catalytic recyclability and stability and can be a potential catalyst for the treatment of organic pollutants in aqueous solutions.


2017 ◽  
Vol 126 (1C) ◽  
pp. 21
Author(s):  
Võ Thị Thanh Châu ◽  
Hoàng Văn Đức

<p>In the present paper, a synthesis of MIL-101 by hydrothermal process was demonstrated. The obtained samples were characterized by powder X-ray diffraction (PXRD), transmission electron microscope (TEM), nitrogen adsorption/desorption isotherms at 77K, X-ray photoelectron spectroscopy (XPS). The results showed that MIL-101 synthesized by optimal conditions exhibited high crystallinity and surface area. The obtained MIL-101 possesses high stability in water and several organic solvents.</p><p><strong>Keywords:</strong> MIL-101, hydrothermal synthesis, metal organic framework-101. </p>


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