Light-Induced Transformation of Nanostructured V3O7-H2O to V2O5
Abstract
In the present work, light-induced phase transformation of a transition metal oxide has been observed and studied. This phase transformation occurs between two different oxides of vanadium, prepared by sol-gel chemistry, namely from V 3 O 7 ·H 2 O to V 2 O 5 under laser irradiation as low as ~0.31 kW/cm 2 . An interesting feature of this phase transformation is found to be its athermal origin. V 3 O 7 ·H 2 O to V 2 O 5 transformation was investigated by Raman spectroscopy in both air and Ar ambient. Raman spectroscopy was also employed to rule out the heating effects and measure the temperature during this transformation which is as low as 25-29 C (i.e., measurements performed at room temperature). In contrast, it was observed that the same transformation occurs at 350 C when it is driven thermally by annealing samples for 10 minutes. Further, the present work explored kinetics of the light-induced V 3 O 7 ·H 2 O to V 2 O 5 transformation by photoluminescence. The kinetics suggests 1D nucleation and growth from predetermined nucleation sites.
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- OSU Theses [15752]