Purely Visible-Light-Induced Photochromism in Ag–TiO2 Nanoheterostructures

• DOI: 10.1021/acs.langmuir.6b04474
• Publication Date: 2017-05-02T14:10:36Z
• Authors: D. M. Tobaldi; M. J. Hortigüela ...; G. Otero-Irurueta; M. K. Singh; R. C. Pullar; M. P. Seabra; J. A. Labrincha
• Keywords: Visible spectrum; Green-light

We report titania nanoheterostructures decorated with silver, exhibiting tuneable photochromic properties for the first time when stimulated only by visible white light (domestic indoor lamp), no UV wavelengths. Photochromic materials show reversible color changes under exposure. However, all inorganic nanoparticles (NPs) require to operate. Conventionally, multicolor photochromism in Ag–TiO2 films involves a change brownish-gray during UV-light irradiation (i.e., reduction of Ag+ Ag0) and (re)bleaching (re)oxidation Ag0 colorless Ag+) upon visible-light In this work, on contrary, we demonstrate visible-light-induced (ranging from yellow violet) 1–10 mol % Ag-modified NPs using both spectroscopic colorimetric CIEL*a*b* analyses. This is not bleaching UV-induced but itself exposure light, it shown be completely different mechanism—driven interfacial charge transfer an electron valence band TiO2 that AgxO clusters surround titania—to usual UV-triggered reported titania-based materials. The quantity Ag or dictated magnitude degree tuneability change, pale dark blue, rapid after few seconds, intensity red shift surface plasmon resonance induced also increased. effect was annealing at 100 °C/15 min. Photocatalytic activity assessed against abatement nitrogen oxide pollutants, interior use, therefore showing coexistence photocatalysis—both triggered same wavelength—in material, making multifunctional material. Moreover, explain why X-ray photoelectron spectroscopy unreliable technique such