Insights into the Exfoliation Process of V2O5· nH2O Nanosheet Formation Using Real-Time 51V NMR
Journal article, 2019

Copyright © 2019 American Chemical Society. Nanostructured hydrated vanadium oxides (V2O5·nH2O) are actively being researched for applications in energy storage, catalysis, and gas sensors. Recently, a one-step exfoliation technique for fabricating V2O5·nH2O nanosheets in aqueous media was reported; however, the underlying mechanism of exfoliation has been challenging to study. Herein, we followed the synthesis of V2O5·nH2O nanosheets from the V2O5 and VO2 precursors in real time using solution- and solid-state 51V NMR. Solution-state 51V NMR showed that the aqueous solution contained mostly the decavanadate anion [H2V10O28]4- and the hydrated dioxovanadate cation [VO2·4H2O]+, and during the exfoliation process, decavanadate was formed, while the amount of [VO2·4H2O]+ remained constant. The conversion of the solid precursor V2O5, which was monitored with solid-state 51V NMR, was initiated when VO2 was in its monoclinic forms. The dried V2O5·nH2O nanosheets were weakly paramagnetic because of a minor content of isolated V4+. Its solid-state 51V signal was less than 20% of V2O5 and arose from diamagnetic V4+ or V5+.This study demonstrates the use of real-time NMR techniques as a powerful analysis tool for the exfoliation of bulk materials into nanosheets. A deeper understanding of this process will pave the way to tailor these important materials. ©

Author

Ahmed S. Etman

Stockholm University

Linköping University

Alexandria University

Andrew J. Pell

Stockholm University

P Svedlindh

Uppsala University

Niklas Hedin

Stockholm University

Xiaodong Zou

Stockholm University

Junliang Sun

Stockholm University

Beijing University of Technology

Diana Bernin

Stockholm University

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Engineering Design

ACS Omega

24701343 (eISSN)

Vol. 4 6 10899-10905

Subject Categories

Physical Chemistry

Materials Chemistry

Other Chemical Engineering

DOI

10.1021/acsomega.9b00727

More information

Latest update

7/12/2019