Enhanced light absorption of TiO2 in the near-ultraviolet band by Au nanoparticles

We propose a scheme to enhance near-UV band absorption of a rutile TiO2 nanoparticle by placing Au nanoparticles in its neighborhood. The discrete-dipole approximation method was employed to calculate the absorption spectrum of pure rutile TiO2 and that of TiO2 mixed with Au nanoparticles. The results indicate that pure rutile TiO2 has its maximum absorption located in the deep-UV band. With the existence of Au nanoparticles, a significant light harvesting effect occurs, and this maximum shifts to the near-UV band, where usual excitation wavelength falls. (C) 2010 Optical Society of America