Unexpected Long-Term Instability of ZnO Nanowires Protected by a TiO2 Shell

We revealed the aggravated instability of (0001)-oriented ZnO nanowires when they were deposited by a TiO2 shell even under ambient conditions. Trace UV photons from daylight and moisture from air, which generally have negligible effects on bare ZnO nanowires, can obviously enhance their photocorrosion due to the high bandgap of TiO2 as well as this conformal core-shell heterostructure.