Preparation of Porous Titanium Dioxide Film Loaded with Ag Particles and Its Photochromic Properties

• 1、School of Physics, Northwest University, Xi'an 710069

Abstract：To improve the photochromic properties of titanium dioxide film loaded with Ag particles, PEG was added to the gel of titanium dioxide which was used to prepare the film, expecting that porous film forms and thus accelerates the photochromic process. It was found that dense pores with diameters larger than several tens nanometers form in the film when PEG2000 or PEG4000 was added, and the porous film exhibit obvious photochromic phenomenon. Diameter of the pores in the film increases as amount or relative molecular mass of PEG increases, however, pores with diameter 50~100nm are most helpful for improving the photochromic speed. Those pores can confine the shape and size of the Ag particles deposited on their surfaces in a certain degree, but the confinement will become weaker as the pores become larger. Shape, size and density of the Ag particles, which determine the positions and shapes of spectral holes burning in the differential absorption spectrum, mostly depend on the time for Ag deposition. Overlong Ag depositing time may induce extra "burning holes" and make the "burning holes" wide. All these results will be helpful to optimize and control the photochromic properties of the Ag/titanium dioxide composite films prepared by sol-gel method.

Keywords： condensed matter physics titanium dioxide film loaded with Ag porous film photochromism