Gram-scale selective synthesis of WO_3−x nanorods and (NH₄)_xWO₃ ammonium tungsten bronzes with tunable plasmonic properties

Abstract

Localized surface plasmon resonance properties in unconventional materials like metal oxides or chalcogenide semiconductors have been studied for use in signal detection and analysis in biomedicine and photocatalysis. We devised...

Lithium confinement and dynamics in hexagonal and monoclinic tungsten oxide nanocrystals: a 7Li solid state NMR study

“…1 The number of examples where band theory alone can provide an adequate property description is limited and mostly confined to compounds of the 4d and 5d series such as A x WO 3 or the Magneli-type phases M n O 3n−2 . 2 Tungsten trioxide has long been studied for its structural, electronic, and electrochromic properties, and it has become a hot topic in fields like photoluminescense, 3 NIR light-shielding, 4,5 plasmonics, 6,7 thermoelectrics, [8][9][10][11] superconductivity, 1,12,13 gas sensing, 14 supercapacitors, 15 batteries, [16][17][18] catalysis 19 or photocatalysis, 20 and for water splitting devices 21 and solar cells. 22,23 Tungsten trioxide (WO 3 ) has a ReO 3 -type structure with corner-sharing WO 6 octahedra.…”

“…54 Furthermore, cations can be adsorbed on the nanoparticle surface due to the negative zeta surface potential. 7 In this article, we expand the Li x WO 3 bronze family by the mixed hexagonal lithium ammonium bronze Li x (NH 4 ) y WO 3 where the Li + and ammonium cations are accommodated in the hexagonal channels of the bronze.…”

“…Information about the types, organization and dynamics of the cations incorporated in the structure can be obtained using solid state nuclear magnetic resonance (ssNMR) spectroscopy. The two NMR active isotopes of lithium 6 Li (I = 1, 7.6%) and 7 Li (I = 3/2, 92.4%) make ssNMR spectroscopy an ideal tool for distinguishing different Li + sites based on differences in shielding. Also, one-and two-dimensional NMR experiments based on cross-polarization (CP), which relies on through space dipole-dipole couplings, allow probing the proximity to other NMR active nuclei.…”

“…Li x (NH 4 + ) y WO 3 was compared to the (NH 4 + ) x WO 3 bronze 7 in terms of temperature stability and particle morphology. Different types of Li + cations were determined using 7 Li-NMR and 1 H- 7 Li cross-polarization (CP) NMR spectroscopy. Using the cross-polarization buildup curves, we could obtain qualitative information about the interatomic distances between the 1 H and 7 Li species in the structure and on the surface of the lithium-enriched Li x (NH 4 + ) y WO 3 tungsten bronze particles.…”

Anisotropic growth of ZnO nanoparticles driven by the structure of amine surfactants: the role of surface dynamics in nanocrystal growth

“…In this context, the use of amines with long fatty chains as surfactants, such as the archetypal oleylamine, 40 is very popular to achieve good control of the morphology of NCs. The high boiling point of oleylamine, above 360 °C, allowed using it in thermolytic reduction processes whether in a “heat up” approach, 41–49 or through the so-called “hot-injection” 48–51 technique. Hexadecylamine, dodecylamine and octylamine are also extensively used under milder conditions for the formation of metallic, II–VI or III–V semiconductor NCs.…”