Resonant Two-photon Oxidation in Vanadium Oxyhydrate Nanowires Above a Threshold Laser Intensity

Abstract

The present work discloses the unusual photooxidation observed for V 3O 7•H 2O nanowires under 514 nm excitation above a threshold intensity of 0.30 kW/cm 2. We explicate this phenomenon by in-situ Raman and photoluminescence spectroscopy at varying laser intensities as well as models for the transformation kinetics and energy band structure associated with H 2OVO 5 octahedron. The photooxidation is found to be triggered by two-photon cleavage of the H 2O-V bond through excitation via nonbonding d-states. Subsequently, V 3O 7 spontaneously oxidizes to V 2O 5. However, the competing process of H 2O's rebonding is also realized. Hence, transformation to V 2O 5 occurs only if the H 2O-V bond-cleavage rate exceeds a threshold, pushing the number of concomitantly broken bonds in the smallest structural unit to a critical number. © 2012 American Chemical Society.

Department(s)

Chemistry

International Standard Serial Number (ISSN)

1932-7447

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2012 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jan 2012

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