PHOTOREDOX LASER CHEMISTRY OF TRANSITION-METAL OXIDES

We describe two-color laser excitation of tungsten oxide in ambient ai r to effect a fully reversible photoredox cycle. One color is infrared , apparently functioning as heat, and the other is visible or shorter wavelength, but not necessarily super bandgap, apparently supplying el ectronic excitation. In the case of either tungsten oxide or molybdenu m oxide, the process can be monitored using a very strong set of Raman spectroscopic features. This process could find application in optica l data storage and may be a generally useful strategy for manipulating transition metal oxides.