S. Chang, Boyce; Thomas, Brijith; Chen, Jiahao; D. Tevis, Ian; Karanja, Paul; Çınar, Simge; Venkatesh, Amrit; J. Rossini, Aaron; M. Thuo, Martin
Ambient synthesis of nanomaterials by in situ heterogeneous metal/ligand reactions
Coordination polymers are ideal synthons in creating high aspect ratio nanostructures, however, conventional synthetic methods are often restricted to batch-wise and costly processes. Herein, we demonstrate a non-traditional, frugal approach to synthesize 1D coordination polymers by in situ etching of zerovalent metal particle precursors. This procedure is denoted as the…
Active site isolation in bismuth-poisoned Pd/SiO2 catalysts for selective hydrogenation of furfural
Cherkasov, Nikolay; Expósito, Antonio José; Aw, Moom Sinn; Fernández-García, Javier; Huband, Steven; Sloan, Jeremy; Paniwnyk, Larysa; Rebrov, Evgeny V.
Active site isolation in furfural (FA) hydrogenation was studied by poisoning a Pd catalyst with bismuth. A solution of FA in water was hydrogenated over a 5?wt% Pd/SiO2 catalyst in a batch reactor at various reaction temperatures and pressures. Furfuryl alcohol (FAL) was an intermediate product which was further hydrogenated…
Stabilizing Silver Window Electrodes for Organic Photovoltaics Using a Mercaptosilane Monolayer
Lee, Jaemin; Walker, Marc; Varagnolo, Silvia; Huband, Steven; Hatton, Ross A.
A single layer of the bifunctional molecule 3-mercaptopropyltrimethoxysilane is shown to be remarkably effective at improving the stability of optically thin silver film electrodes toward spontaneous morphological change and oxidation by airborne sulfur. Inclusion of this layer in the novel transparent electrode WO3(30 nm)/silver (13 nm)/solgel ZnO (27 nm) at…
Two Growth Mechanisms of Thiol-Capped Gold Nanoparticles Controlled by Ligand Chemistry
Chen, Xuelian; Wei, Meng; Jiang, Shaohua; Förster, Stephan
Thiols play an important role in the synthesis of well-defined nanoparticles (NPs) with tailored properties, but their effects on the formation kinetics of NPs are still under investigation. Here, we used in situ small-angle X-ray scattering (SAXS)/UVvis spectroscopy and time-dependent transmission electron microscopy (TEM) to elucidate the role of thiols…
An in situ SAXS investigation of the formation of silver nanoparticles and bimetallic silvergold nanoparticles in controlled wet-chemical reduction synthesis
F. Garcia, Paulo R. A.; Prymak, Oleg; Grasmik, Viktoria; Pappert, Kevin; Wlysses, Wagner; Otubo, Larissa; Epple, Matthias; P. Oliveira, Cristiano L.
We present a study on the formation of silver (Ag) and bimetallic silvergold (AgAu) nanoparticlesmonitored by in situ SAXS as well as by ex situ TEM, XRD and UV-vis analysis in a flow reactor at controlled reaction temperature. The formation mechanism of the nanoparticles is derived from the structural parameters…
Ultrathin Homogenous AuNP Monolayers as Tunable Functional Substrates for Surface-Assisted Laser Desorption/Ionization of Small Biomolecules
Liu, Zhen; Zhang, Peng; Kister, Thomas; Kraus, Tobias; Volmer, Dietrich A.
A series of ultrathin, homogenous gold nanoparticle (AuNP) substrates for surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) were prepared using a simple air/water interface approach. These SALDI substrates enabled soft ionization and provided significant improvements in terms of signal intensities and reduced background levels in comparison to other AuNP morphologies for
Nanocrystalline ODS-iron aluminide by cryo-milling: consolidation, microstructure and mechanical behavior
Sarma, S. Sudhakara; Prasad, Satya; Joardar, Joydip; Suresh, K.; Reddy, A. V.; Vijay, R.
Nanocrystalline oxide dispersion strengthened (ODS) Fe-25 at% Al alloy was produced by cryo-milling of elemental powder blend and Y2O3. The as-milled powder was consolidated by hot extrusion. The Microstructure and mechanical properties of the consolidated material were evaluated. Fracture of powder particles during milling was dominant due to cryo temperatures…
Precipitation in original Duralumin A-U4G versus modern 2017A alloy
Brunet, Magali; Malard, Benoit; Ratel-Ramond, Nicolas; Deshayes, Christophe; Joulié, Sébastien; Warot-Fonrose, Bénédicte; Sciau, Philippe; Douin, Joël; De Geuser, Frédéric; Deschamps, Alexis
Precipitation in Duralumin, a historic quaternary alloy of the type: AlCuMgSi, was never fully studied nor observed by current electron microscopy techniques. This article presents the full characterization and comparison of two alloys: a Duralumin (A-U4G) from the 1950s collected on a vintage aircraft and its modern equivalent: a 2017A…
Quantitative Analysis of Semiconductor Nanocrystal Ensemble Optical Extinction
Staller, Corey M.; Agrawal, Ankit; Gibbs, Stephen L.; Cabezas, Camila A. Saez; Johns, Robert W.; Milliron, Delia J.
The optical extinction coefficients of localized surface plasmon resonance (LSPR) in doped semiconductor nanocrystals (NCs) have intensities determined by the free charge carrier concentration and the mechanisms for damping the oscillation of those free carriers. We investigate the dependence of the extinction coefficient of tin-doped indium oxide (ITO) NCs on…
Investigating Particle Size Effects in Catalysis by Applying a Size-Controlled and Surfactant-Free Synthesis of Colloidal Nanoparticles in Alkaline Ethylene Glycol: Case Study of the Oxygen Reduction Reaction on Pt
Quinson, Jonathan; Inaba, Masanori; Neumann, Sarah; Swane, Andreas A.; Bucher, J.; Simonsen, Søren B.; Theil Kuhn, Luise; Kirkensgaard, Jacob J. K.; Jensen, Kirsten M. Ø.; Oezaslan, Mehtap; Kunz, Sebastian; Arenz, Matthias
Colloidal platinum nanoparticles are obtained via a surfactant-free polyol process in alkaline ethylene glycol. In this popular synthesis, ethylene glycol functions as solvent and reducing agent. The preparation procedure is known for its reproducibility to obtain 1–2 nm nanoparticles, but at the same time the controlled preparation of larger nanoparticles…