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Osama Shekhah - One of the best experts on this subject based on the ideXlab platform.

  • the growth of photoactive porphyrin based mof thin films using the Liquid Phase Epitaxy approach and their optoelectronic properties
    Materials, 2019
    Co-Authors: Guy Olivier Ngongang Ndjawa, Osama Shekhah, Mohamed R Tchalala, Jafar Iqbal Khan, Ahmed Mansour, Justyna Czabanjoźwiak, Lukasz Weselinski, Hassan Ait Ahsaine, Aram Amassian, Mohamed Eddaoudi
    Abstract:

    This study reports on the optoelectronic properties of porphyrin-based metal–organic framework (MOF) thin films fabricated by a facile Liquid-Phase Epitaxy approach. This approach affords the growth of MOF thin films that are free of morphological imperfections, more suitable for optoelectronic applications. Chemical modifications such as the porphyrin ligand metallation have been found to preserve the morphology of the grown films making this approach particularly suitable for molecular alteration of MOF thin film optoelectronic properties without compromising its mesoscale morphology significantly. Particularly, the metallation of the ligand was found to be effective to tune the MOF bandgap. These porphyrin-based MOF thin films were shown to function effectively as donor layers in solar cells based on a Fullerene-C60 acceptor. The ability to fabricate MOF solar cells free of a Liquid-Phase acceptor greatly simplifies device fabrication and enables pairing of MOFs as light absorbers with a wide range of acceptors including non-fullerene acceptors.

  • advanced fabrication method for the preparation of mof thin films Liquid Phase Epitaxy approach meets spin coating method
    ACS Applied Materials & Interfaces, 2016
    Co-Authors: Valeriya Chernikova, Osama Shekhah, Mohamed Eddaoudi
    Abstract:

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal–organic framework (MOF) thin films. Building on the attractive features of the Liquid-Phase Epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide...

  • the Liquid Phase Epitaxy approach for the successful construction of ultra thin and defect free zif 8 membranes pure and mixed gas transport study
    Chemical Communications, 2014
    Co-Authors: Osama Shekhah, Raja Swaidan, Youssef Belmabkhout, Marike Du Plessis, Tia Jacobs, Leonard J Barbour, Ingo Pinnau, Mohamed Eddaoudi
    Abstract:

    The Liquid-Phase Epitaxy (LPE) method was effectively implemented to deliberately grow/construct ultrathin (0.5–1 μm) continuous and defect-free ZIF-8 membranes. Permeation properties of different gas pair systems (O2–N2, H2–CO2, CO2–CH4, C3H6–C3H8, CH4–n-C4H10) were studied using the time lag technique.

  • the Liquid Phase Epitaxy method for the construction of oriented zif 8 thin films with controlled growth on functionalized surfaces
    Chemical Communications, 2013
    Co-Authors: Osama Shekhah, Mohamed Eddaoudi
    Abstract:

    Highly-oriented ZIF-8 thin films with controllable thickness were grown on an –OH-functionalized Au substrate using the Liquid Phase Epitaxy method at room temperature, as evidenced by SEM and PXRD. The adsorption–desorption properties of the resulting ZIF-8 thin film were investigated for various VOCs using the QCM technique.

  • magnetic cores with porous coatings growth of metal organic frameworks on particles using Liquid Phase Epitaxy
    Advanced Functional Materials, 2013
    Co-Authors: Martin E Silvestre, Osama Shekhah, Matthias Franzreb, Peter G Weidler, Christof Woll
    Abstract:

    A novel method for the homogeneous coating of magnetic nanoparticles with metal organic frameworks (MOFs) is reported. Using a Liquid Phase Epitaxy process, a well-defined number of [Cu3(btc)2]nH2O, HKUST-1, layers are grown on COOH terminated silica magnetic beads. The structure and porosity of the deposited MOF coatings are studied using X-ray diffraction and BET analysis. In addition, size and shape of the fabricated composites are analyzed by transmission electron microscopy. Potential applications of particle based MOF films include catalytic coatings and chromatographic media.

Christof Woll - One of the best experts on this subject based on the ideXlab platform.

  • zif 8 surmof membranes synthesized by au assisted Liquid Phase Epitaxy for application in gas separation
    Chemie Ingenieur Technik, 2016
    Co-Authors: Elvia Valadez P Sanchez, Christof Woll, Hartmut Gliemann, Katja Haassanto, Roland Dittmeyer
    Abstract:

    Metal-organic frameworks (MOFs) exhibit a huge potential for gas separation. ZIF-8 is an interesting candidate due to its high thermal stability and its pore properties. By Liquid Phase Epitaxy, the growth of the highly oriented surface-anchored MOF ZIF-8 on non-porous and porous surfaces has been proven. The preparation of monolithic ZIF-8 thin films supported by porous α-Al2O3 substrates modified by a thin layer of Au is investigated. The layer-by-layer deposition process accomplished via a dipping procedure results in the formation of defect- or crack-free membranes, preliminary characterized by the determination of ethane and ethene permeance.

  • chiral porous metacrystals employing Liquid Phase Epitaxy to assemble enantiopure metal organic nanoclusters into molecular framework pores
    ACS Nano, 2016
    Co-Authors: Tobias Neumann, Wolfgang Wenzel, Lei Zhang, Jian Zhang, Christof Woll
    Abstract:

    We describe the fabrication of hybrid yet well-ordered porous nanoparticle (NP) arrays with full three-dimensional periodicity by embedding nanometer-sized metal–organic clusters (MOCs) into metal–organic frameworks (MOFs). Although conventional NP@MOF encapsulation procedures failed for these fairly large (1.66 nm diameter) NPs, we achieved maximum loading efficiency (one NP per pore) by using a modified Liquid Phase Epitaxy (LPE) layer-by-layer approach to grow and load the MOF. The preformed NPs, homochiral Ti4(OH)4(R/S-BINOL)6 clusters (Ti-MOC, BINOL = 1,1′-bi-2-naphthol), formed a regular lattice inside the pores of an achiral HKUST-1 (or Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate) MOF thin film. Exposure to the different enantiomers of methyl lactate revealed that the NP@MOF metacrystal is quite efficient regarding enantiomer recognition and separation. The approach presented here is also suited for other MOF types and expected to provide a substantial stimulus for the fabrication of metacrystals,...

  • magnetic cores with porous coatings growth of metal organic frameworks on particles using Liquid Phase Epitaxy
    Advanced Functional Materials, 2013
    Co-Authors: Martin E Silvestre, Osama Shekhah, Matthias Franzreb, Peter G Weidler, Christof Woll
    Abstract:

    A novel method for the homogeneous coating of magnetic nanoparticles with metal organic frameworks (MOFs) is reported. Using a Liquid Phase Epitaxy process, a well-defined number of [Cu3(btc)2]nH2O, HKUST-1, layers are grown on COOH terminated silica magnetic beads. The structure and porosity of the deposited MOF coatings are studied using X-ray diffraction and BET analysis. In addition, size and shape of the fabricated composites are analyzed by transmission electron microscopy. Potential applications of particle based MOF films include catalytic coatings and chromatographic media.

  • deposition of metal organic frameworks by Liquid Phase Epitaxy the influence of substrate functional group density on film orientation
    Materials, 2012
    Co-Authors: Osama Shekhah, Xia Stammer, Hasan K Arslan, Bjorn Schupbach, Andreas Terfort, Christof Woll
    Abstract:

    The Liquid Phase Epitaxy (LPE) of the metal-organic framework (MOF) HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs) on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA), 4’-carboxyterphenyl-4-methanethiol (TPMTA) and 9-carboxy-10-(mercaptomethyl)triptycene (CMMT). The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100) direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111) direction.

  • fabrication of free standing ultrathin films of porous metal organic frameworks by Liquid Phase Epitaxy and subsequent delamination
    Physica Status Solidi-rapid Research Letters, 2010
    Co-Authors: Masih Darbandi, Osama Shekhah, Hasan K Arslan, Asif Bashir, Alexander Birkner, Christof Woll
    Abstract:

    In this work we describe an approach to fabricate MOF (metal-organic framework) platelets with predefined shapes and well-defined thicknesses. The process is based on growing thin, highly oriented and ordered MOF films by selective Liquid-Phase Epitaxy on prestructured organic substrates. In a second step, the MOF platelets are delaminated employing a lift-off process. The freestanding MOF platelets were characterized with TEM and SEM, which showed no evidence of fracture or deformation of the delaminated shapes. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Mohamed Eddaoudi - One of the best experts on this subject based on the ideXlab platform.

  • the growth of photoactive porphyrin based mof thin films using the Liquid Phase Epitaxy approach and their optoelectronic properties
    Materials, 2019
    Co-Authors: Guy Olivier Ngongang Ndjawa, Osama Shekhah, Mohamed R Tchalala, Jafar Iqbal Khan, Ahmed Mansour, Justyna Czabanjoźwiak, Lukasz Weselinski, Hassan Ait Ahsaine, Aram Amassian, Mohamed Eddaoudi
    Abstract:

    This study reports on the optoelectronic properties of porphyrin-based metal–organic framework (MOF) thin films fabricated by a facile Liquid-Phase Epitaxy approach. This approach affords the growth of MOF thin films that are free of morphological imperfections, more suitable for optoelectronic applications. Chemical modifications such as the porphyrin ligand metallation have been found to preserve the morphology of the grown films making this approach particularly suitable for molecular alteration of MOF thin film optoelectronic properties without compromising its mesoscale morphology significantly. Particularly, the metallation of the ligand was found to be effective to tune the MOF bandgap. These porphyrin-based MOF thin films were shown to function effectively as donor layers in solar cells based on a Fullerene-C60 acceptor. The ability to fabricate MOF solar cells free of a Liquid-Phase acceptor greatly simplifies device fabrication and enables pairing of MOFs as light absorbers with a wide range of acceptors including non-fullerene acceptors.

  • advanced fabrication method for the preparation of mof thin films Liquid Phase Epitaxy approach meets spin coating method
    ACS Applied Materials & Interfaces, 2016
    Co-Authors: Valeriya Chernikova, Osama Shekhah, Mohamed Eddaoudi
    Abstract:

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal–organic framework (MOF) thin films. Building on the attractive features of the Liquid-Phase Epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide...

  • the Liquid Phase Epitaxy approach for the successful construction of ultra thin and defect free zif 8 membranes pure and mixed gas transport study
    Chemical Communications, 2014
    Co-Authors: Osama Shekhah, Raja Swaidan, Youssef Belmabkhout, Marike Du Plessis, Tia Jacobs, Leonard J Barbour, Ingo Pinnau, Mohamed Eddaoudi
    Abstract:

    The Liquid-Phase Epitaxy (LPE) method was effectively implemented to deliberately grow/construct ultrathin (0.5–1 μm) continuous and defect-free ZIF-8 membranes. Permeation properties of different gas pair systems (O2–N2, H2–CO2, CO2–CH4, C3H6–C3H8, CH4–n-C4H10) were studied using the time lag technique.

  • the Liquid Phase Epitaxy method for the construction of oriented zif 8 thin films with controlled growth on functionalized surfaces
    Chemical Communications, 2013
    Co-Authors: Osama Shekhah, Mohamed Eddaoudi
    Abstract:

    Highly-oriented ZIF-8 thin films with controllable thickness were grown on an –OH-functionalized Au substrate using the Liquid Phase Epitaxy method at room temperature, as evidenced by SEM and PXRD. The adsorption–desorption properties of the resulting ZIF-8 thin film were investigated for various VOCs using the QCM technique.

Stephen Maldonado - One of the best experts on this subject based on the ideXlab platform.

  • electrochemical Liquid Phase Epitaxy ec lpe a new methodology for the synthesis of crystalline group iv semiconductor epifilms
    Journal of the American Chemical Society, 2017
    Co-Authors: Joshua Demuth, Eli Fahrenkrug, Titilayo Shodiya, Julia I. Deitz, Tyler J. Grassman, Stephen Maldonado
    Abstract:

    Deposition of epitaxial germanium (Ge) thin films on silicon (Si) wafers has been achieved over large areas with aqueous feedstock solutions using electrochemical Liquid Phase Epitaxy (ec-LPE) at low temperatures (T ≤ 90 °C). The ec-LPE method uniquely blends the simplicity and control of traditional electrodeposition with the material quality of melt growth. A new electrochemical cell design based on the compression of a Liquid metal electrode into a thin cavity that enables ec-LPE is described. The epitaxial nature, low strain character, and crystallographic defect content of the resultant solid Ge films were analyzed by electron backscatter diffraction, scanning transmission electron microscopy, high resolution X-ray diffraction, and electron channeling contrast imaging. The results here show the first step toward a manufacturing infrastructure for traditional crystalline inorganic semiconductor epifilms that does not require high temperature, gaseous precursors, or complex apparatus.

  • Electrochemical Liquid Phase Epitaxy (ec-LPE): A New Methodology for the Synthesis of Crystalline Group IV Semiconductor Epifilms
    2017
    Co-Authors: Joshua Demuth, Eli Fahrenkrug, Titilayo Shodiya, Julia I. Deitz, Tyler J. Grassman, Stephen Maldonado
    Abstract:

    Deposition of epitaxial germanium (Ge) thin films on silicon (Si) wafers has been achieved over large areas with aqueous feedstock solutions using electrochemical Liquid Phase Epitaxy (ec-LPE) at low temperatures (T ≤ 90 °C). The ec-LPE method uniquely blends the simplicity and control of traditional electrodeposition with the material quality of melt growth. A new electrochemical cell design based on the compression of a Liquid metal electrode into a thin cavity that enables ec-LPE is described. The epitaxial nature, low strain character, and crystallographic defect content of the resultant solid Ge films were analyzed by electron backscatter diffraction, scanning transmission electron microscopy, high resolution X-ray diffraction, and electron channeling contrast imaging. The results here show the first step toward a manufacturing infrastructure for traditional crystalline inorganic semiconductor epifilms that does not require high temperature, gaseous precursors, or complex apparatus

Joshua Demuth - One of the best experts on this subject based on the ideXlab platform.

  • electrochemical Liquid Phase Epitaxy ec lpe a new methodology for the synthesis of crystalline group iv semiconductor epifilms
    Journal of the American Chemical Society, 2017
    Co-Authors: Joshua Demuth, Eli Fahrenkrug, Titilayo Shodiya, Julia I. Deitz, Tyler J. Grassman, Stephen Maldonado
    Abstract:

    Deposition of epitaxial germanium (Ge) thin films on silicon (Si) wafers has been achieved over large areas with aqueous feedstock solutions using electrochemical Liquid Phase Epitaxy (ec-LPE) at low temperatures (T ≤ 90 °C). The ec-LPE method uniquely blends the simplicity and control of traditional electrodeposition with the material quality of melt growth. A new electrochemical cell design based on the compression of a Liquid metal electrode into a thin cavity that enables ec-LPE is described. The epitaxial nature, low strain character, and crystallographic defect content of the resultant solid Ge films were analyzed by electron backscatter diffraction, scanning transmission electron microscopy, high resolution X-ray diffraction, and electron channeling contrast imaging. The results here show the first step toward a manufacturing infrastructure for traditional crystalline inorganic semiconductor epifilms that does not require high temperature, gaseous precursors, or complex apparatus.

  • Electrochemical Liquid Phase Epitaxy (ec-LPE): A New Methodology for the Synthesis of Crystalline Group IV Semiconductor Epifilms
    2017
    Co-Authors: Joshua Demuth, Eli Fahrenkrug, Titilayo Shodiya, Julia I. Deitz, Tyler J. Grassman, Stephen Maldonado
    Abstract:

    Deposition of epitaxial germanium (Ge) thin films on silicon (Si) wafers has been achieved over large areas with aqueous feedstock solutions using electrochemical Liquid Phase Epitaxy (ec-LPE) at low temperatures (T ≤ 90 °C). The ec-LPE method uniquely blends the simplicity and control of traditional electrodeposition with the material quality of melt growth. A new electrochemical cell design based on the compression of a Liquid metal electrode into a thin cavity that enables ec-LPE is described. The epitaxial nature, low strain character, and crystallographic defect content of the resultant solid Ge films were analyzed by electron backscatter diffraction, scanning transmission electron microscopy, high resolution X-ray diffraction, and electron channeling contrast imaging. The results here show the first step toward a manufacturing infrastructure for traditional crystalline inorganic semiconductor epifilms that does not require high temperature, gaseous precursors, or complex apparatus