TY - JOUR

T1 - W18O49 Nanowhiskers Decorating SiO2 Nanofibers

T2 - Lessons from in situ SEM/TEM growth to large scale synthesis and fundamental structural understanding

AU - Kundrat, Vojtech

AU - Bukvisova, Kristyna

AU - Novak, Libor

AU - Prucha, Lukas

AU - Houben, Lothar

AU - Zalesak, Jakub

AU - Vukusic, Antonio

AU - Holec, David

AU - Tenne, Reshef

AU - Pinkas, Jiri

N1 - Publisher Copyright: © 2023 The Authors. Published by American Chemical Society

PY - 2023/12/5

Y1 - 2023/12/5

N2 - Tungsten suboxide W 18O 49 nanowhiskers are a material of great interest due to their potential high-end applications in electronics, near-infrared light shielding, catalysis, and gas sensing. The present study introduces three main approaches for the fundamental understanding of W 18O 49 nanowhisker growth and structure. First, W 18O 49 nanowhiskers were grown from γ-WO 3/a-SiO 2 nanofibers in situ in a scanning electron microscope (SEM) utilizing a specially designed microreactor (μReactor). It was found that irradiation by the electron beam slows the growth kinetics of the W 18O 49 nanowhisker, markedly. Following this, an in situ TEM study led to some new fundamental understanding of the growth mode of the crystal shear planes in the W 18O 49 nanowhisker and the formation of a domain (bundle) structure. High-resolution scanning transmission electron microscopy analysis of a cross-sectioned W 18O 49 nanowhisker revealed the well-documented pentagonal Magnéli columns and hexagonal channel characteristics for this phase. Furthermore, a highly crystalline and oriented domain structure and previously unreported mixed structural arrangement of tungsten oxide polyhedrons were analyzed. The tungsten oxide phases found in the cross section of the W 18O 49 nanowhisker were analyzed by nanodiffraction and electron energy loss spectroscopy (EELS), which were discussed and compared in light of theoretical calculations based on the density functional theory method. Finally, the knowledge gained from the in situ SEM and TEM experiments was valorized in developing a multigram synthesis of W 18O 49/a-SiO 2 urchin-like nanofibers in a flow reactor.

AB - Tungsten suboxide W 18O 49 nanowhiskers are a material of great interest due to their potential high-end applications in electronics, near-infrared light shielding, catalysis, and gas sensing. The present study introduces three main approaches for the fundamental understanding of W 18O 49 nanowhisker growth and structure. First, W 18O 49 nanowhiskers were grown from γ-WO 3/a-SiO 2 nanofibers in situ in a scanning electron microscope (SEM) utilizing a specially designed microreactor (μReactor). It was found that irradiation by the electron beam slows the growth kinetics of the W 18O 49 nanowhisker, markedly. Following this, an in situ TEM study led to some new fundamental understanding of the growth mode of the crystal shear planes in the W 18O 49 nanowhisker and the formation of a domain (bundle) structure. High-resolution scanning transmission electron microscopy analysis of a cross-sectioned W 18O 49 nanowhisker revealed the well-documented pentagonal Magnéli columns and hexagonal channel characteristics for this phase. Furthermore, a highly crystalline and oriented domain structure and previously unreported mixed structural arrangement of tungsten oxide polyhedrons were analyzed. The tungsten oxide phases found in the cross section of the W 18O 49 nanowhisker were analyzed by nanodiffraction and electron energy loss spectroscopy (EELS), which were discussed and compared in light of theoretical calculations based on the density functional theory method. Finally, the knowledge gained from the in situ SEM and TEM experiments was valorized in developing a multigram synthesis of W 18O 49/a-SiO 2 urchin-like nanofibers in a flow reactor.

UR - http://www.scopus.com/inward/record.url?scp=85180075677&partnerID=8YFLogxK

U2 - 10.1021/acs.cgd.3c01094

DO - 10.1021/acs.cgd.3c01094

M3 - Article

VL - 24.2024

SP - 378

EP - 390

JO - Crystal growth & design

JF - Crystal growth & design

SN - 1528-7483

IS - 1

ER -