Reversible modulated mid-infrared absorption of Ag/TiO2 by photoinduced interfacial charge transfer

An enhanced mid-infrared absorption in Ag nanoparticles-decorated TiO2 microflowers was reported. It was found that the mid-infrared absorption of the Ag/TiO2 complex depends strongly on the content and size of Ag nanoparticles, the higher the Ag nanoparticles content, the stronger the infrared absorption. The average reflectivity in the entire mid-infrared region of the microflowers drops from 57.6% to 10.5% after Ag nanoparticles decoration. Reversible modulated mid-infrared absorption properties were found in the Ag/TiO2 complexes upon alternative illumination of visible and UV light due to the photoinduced interfacial electron transfer between TiO2 semiconductor and Ag nanoparticles.