scholarly journals Self-arrangement of nanoparticles toward crystalline metal oxides with high surface areas and tunable 3D mesopores

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Hyung Ik Lee ◽  
Yoon Yun Lee ◽  
Dong-Uk Kang ◽  
Kirim Lee ◽  
Young-Uk Kwon ◽  
...  
Keyword(s):  
Metal Oxides ◽  
High Surface ◽  
Surface Areas ◽  
Crystalline Metal

Novel Nanostructured Photoelectrodes - Electrodeposition of Metal Oxides onto Transparent Conducting Oxide Nanofibers

2009 ◽  
Vol 1211 ◽  
Author(s):  
Rainer Ostermann ◽  
Melanie Rudolph ◽  
Derck Schlettwein ◽  
Bernd M Smarsly
Keyword(s):  
Metal Oxides ◽  
High Surface ◽  
Transparent Conducting Oxide ◽  
Dye Sensitized Solar Cells ◽  
Conducting Oxides ◽  
Surface Areas ◽  
Transparent Conducting ◽  
3D Electrodes ◽  
Improved Performance ◽  
Nanostructured Metal Oxides

AbstractNanostructured metal oxides with high surface areas have been shown to be efficient photoelectrodes for light-to-energy conversion in dye-sensitized solar cells (DSCs). In this work we demonstrate the use of nanofibrous mats of transparent conducting oxides (TCOs) as nanostructured electrodes, especially for DSCs. The nanofibers have been obtained by electrospinning suitable inorganic precursors and polymers, followed by calcination to remove the polymer. Afterwards, TiO2 layers were generated on our 3D-electrodes by electrodeposition. An improved performance as DSC was found compared to flat electrodes of similar thickness, validating our approach.

scholarly journals Crystalline metal-organic frameworks (MOFs): synthesis, structure and function

2013 ◽  
Vol 70 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Chandan Dey ◽  
Tanay Kundu ◽  
Bishnu P. Biswal ◽  
Arijit Mallick ◽  
Rahul Banerjee
Keyword(s):  
High Surface ◽  
Metal Organic Frameworks ◽  
Structural Diversity ◽  
Hybrid Network ◽  
Solid Materials ◽  
Guest Molecules ◽  
Surface Areas ◽  
Metal Organic ◽  
And Function ◽  
Crystalline Metal

Metal-organic frameworks (MOFs) are a class of hybrid network supramolecular solid materials comprised of organized organic linkers and metal cations. They can display enormously high surface areas with tunable pore size and functionality, and can be used as hosts for a range of guest molecules. Since their discovery, MOFs have experienced widespread exploration for their applications in gas storage, drug delivery and sensing. This article covers general and modern synthetic strategies to prepare MOFs, and discusses their structural diversity and properties with respect to application perspectives.

A Highly Crystalline Anthracene-Based MOF-74 Series Featuring Electrical Conductivity and Luminescence

2019 ◽  
Author(s):  
Patricia Scheurle ◽  
Andre Mähringer ◽  
Andreas Jakowetz ◽  
Pouya Hosseini ◽  
Alexander Richter ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Metal Ions ◽  
Light Emission ◽  
Block Design ◽  
High Surface ◽  
Visible Spectrum ◽  
Building Blocks ◽  
Divalent Metal Ions ◽  
Conductivity Enhancement ◽  
Surface Areas

Recently, a small group of metal-organic frameworks (MOFs) has been discovered featuring substantial charge transport properties and electrical conductivity, hence promising to broaden the scope of potential MOF applications in fields such as batteries, fuel cells and supercapacitors. In combination with light emission, electroactive MOFs are intriguing candidates for chemical sensing and optoelectronic applications. Here, we incorporated anthracene-based building blocks into the MOF-74 topology with five different divalent metal ions, that is, Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, resulting in a series of highly crystalline MOFs, coined ANMOF-74(M). This series of MOFs features substantial photoluminescence, with ANMOF-74(Zn) emitting across the whole visible spectrum. The materials moreover combine this photoluminescence with high surface areas and electrical conductivity. Compared to the original MOF-74 materials constructed from 2,5-dihydroxy terephthalic acid and the same metal ions Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, we observed a conductivity enhancement of up to six orders of magnitude. Our results point towards the importance of building block design and the careful choice of the embedded MOF topology for obtaining materials with desired properties such as photoluminescence and electrical conductivity.

scholarly journals Mitigating the Agglomeration of Nanofiller in a Mixed Matrix Membrane by Incorporating an Interface Agent

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 328
Author(s):  
Manh-Tuan Vu ◽  
Gloria M. Monsalve-Bravo ◽  
Rijia Lin ◽  
Mengran Li ◽  
Suresh K. Bhatia ◽  
...  
Keyword(s):  
Gas Separation ◽  
Polymer Matrix ◽  
Ion Beam ◽  
High Surface ◽  
Mixed Matrix Membrane ◽  
Mechanical And Thermal Properties ◽  
Separation Membranes ◽  
Surface Areas ◽  
Separation Membrane ◽  
Focus Ion Beam

Nanodiamonds (ND) have recently emerged as excellent candidates for various applications including membrane technology due to their nanoscale size, non-toxic nature, excellent mechanical and thermal properties, high surface areas and tuneable surface structures with functional groups. However, their non-porous structure and strong tendency to aggregate are hindering their potential in gas separation membrane applications. To overcome those issues, this study proposes an efficient approach by decorating the ND surface with polyethyleneimine (PEI) before embedding it into the polymer matrix to fabricate MMMs for CO2/N2 separation. Acting as both interfacial binder and gas carrier agent, the PEI layer enhances the polymer/filler interfacial interaction, minimising the agglomeration of ND in the polymer matrix, which is evidenced by the focus ion beam scanning electron microscopy (FIB-SEM). The incorporation of PEI into the membrane matrix effectively improves the CO2/N2 selectivity compared to the pristine polymer membranes. The improvement in CO2/N2 selectivity is also modelled by calculating the interfacial permeabilities with the Felske model using the gas permeabilities in the MMM. This study proposes a simple and effective modification method to address both the interface and gas selectivity in the application of nanoscale and non-porous fillers in gas separation membranes.

scholarly journals A simple one-step electrochemical deposition of bioinspired nanocomposite for the non-enzymatic detection of dopamine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vijayaraj Kathiresan ◽  
Dinakaran Thirumalai ◽  
Thenmozhi Rajarathinam ◽  
Miri Yeom ◽  
Jaewon Lee ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Electrochemical Characteristics ◽  
Surface Areas ◽  
Electrochemically Reduced Graphene Oxide ◽  
Sensitivity And Selectivity ◽  
Controlled Deposition ◽  
Enzymatic Detection ◽  
Walled Carbon Nanotubes

AbstractA simple and cost-effective electrochemical synthesis of carbon-based nanomaterials for electrochemical biosensor is of great challenge these days. Our study describes a single-step electrochemical deposition strategy to prepare a nanocomposite of electrochemically reduced graphene oxide (ErGO), multi-walled carbon nanotubes (MWCNTs), and polypyrrole (PPy) in an aqueous solution of pH 7.0 for dopamine (DA) detection. The ErGO/MWCNTs/PPy nanocomposites show enhanced electrochemical performance due to the strong π–π* stacking interactions among ErGO, MWCNTs, and PPy. The efficient interaction of the nanocomposites is confirmed by evaluating its physical and electrochemical characteristics using field-emission scanning electron microscopy, Raman spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The deposited nanocomposites are highly stable on the substrates and possess high surface areas, which is vital to improve the sensitivity and selectivity for DA detection. The controlled deposition of the ErGO/MWCNTs/PPy nanocomposites can provide enhanced electrochemical detection of DA. The sensor demonstrates a short time response within 2 s and is a highly sensitive approach for DA detection with a dynamic linear range of 25–1000 nM (R2 = 0.999). The detection limit is estimated to be 2.3 nM, and the sensor sensitivity is calculated to be 8.96 μA μM−1 cm−2, with no distinct responses observed for other biological molecules.

scholarly journals Single and Dual Metal Oxides as Promising Supports for Carbon Monoxide Removal from an Actual Syngas: The Crucial Role of Support on the Selectivity of the Au–Cu System

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 852 ◽  
Author(s):  
Bernay Cifuentes ◽  
Felipe Bustamante ◽  
Martha Cobo
Keyword(s):  
Metal Oxides ◽  
High Surface ◽  
High Surface Area ◽  
Carbon Deposits ◽  
Promising Strategy ◽  
Cu Catalysts ◽  
Dual Metal ◽  
Effect Of The Support ◽  
Lower Capacity

A catalytic screening was performed to determine the effect of the support on the performance of an Au–Cu based system for the removal of CO from an actual syngas. First, a syngas was obtained from reforming of ethanol. Then, the reformer outlet was connected to a second reactor, where Au–Cu catalysts supported on several single and dual metal oxides (i.e., CeO2, SiO2, ZrO2, Al2O3, La2O3, Fe2O3, CeO2-SiO2, CeO2-ZrO2, and CeO2-Al2O3) were evaluated. AuCu/CeO2 was the most active catalyst due to an elevated oxygen mobility over the surface, promoting CO2 formation from adsorption of C–O* and OH− intermediates on Au0 and CuO species. However, its lower capacity to release the surface oxygen contributes to the generation of stable carbon deposits, which lead to its rapid deactivation. On the other hand, AuCu/CeO2-SiO2 was more stable due to its high surface area and lower formation of formate and carbonate intermediates, mitigating carbon deposits. Therefore, use of dual supports could be a promising strategy to overcome the low stability of AuCu/CeO2. The results of this research are a contribution to integrated production and purification of H2 in a compact system.

A facile method to fabricate monolithic alumina–silica aerogels with high surface areas and good mechanical properties

2020 ◽  
Vol 40 (6) ◽  
pp. 2480-2488 ◽  
Author(s):  
Fei Peng ◽  
Yonggang Jiang ◽  
Junzong Feng ◽  
Liangjun Li ◽  
Huafei Cai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Surface ◽  
Silica Aerogels ◽  
Surface Areas ◽  
Monolithic Alumina

Low-Temperature Liquid Precursors of Crystalline Metal Oxides Assisted by Heterogeneous Photocatalysis

2015 ◽  
Vol 27 (16) ◽  
pp. 2608-2613 ◽  
Author(s):  
Iñigo Bretos ◽  
Ricardo Jiménez ◽  
Dulce Pérez-Mezcua ◽  
Norberto Salazar ◽  
Jesús Ricote ◽  
...  
Keyword(s):  
Low Temperature ◽  
Metal Oxides ◽  
Heterogeneous Photocatalysis ◽  
Liquid Precursors ◽  
Temperature Liquid ◽  
Crystalline Metal

Evaluation of a Porous Imine-Based Covalent Organic Framework for Solid-Phase Extraction of Nitroimidazoles

2022 ◽  
Author(s):  
zhikai hong ◽  
yingjiao dong ◽  
ruijie wang ◽  
Guanhua Wang
Keyword(s):  
Thermal Stability ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
High Surface ◽  
Sample Pretreatment ◽  
Phase Extraction ◽  
Covalent Organic Framework ◽  
Framework Materials ◽  
Surface Areas ◽  
Organic Framework

Covalent organic framework materials (COFs), a kind of porous organic material, have excellent potential application in the field of sample pretreatment due to their high surface areas and thermal stability....

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