SPR enhanced photocatalytic properties of Au-dispersed amorphous BaTiO3 nanocomposite thin films

Abstract

Aux/BaTiO3 (x = 0, 5, 10, 15, 25, 35, and 45, where x is mol% of Au) composite thin films dispersed by Au nanoparticles (NPs) were prepared by a sol–gel spin-coating approach. The crystal structure, optical and photocatalytic properties of the films were investigated with a special emphasis on the influences of x. The approximately spherical Au NPs with 20–45 nm in diameter are embedded uniformly in the amorphous BaTiO3 matrix. The absorption peaks appeared at the wavelength from 580 to 620 nm are due to the surface plasmon resonance (SPR) effect of Au NPs, and the SPR peaks generally manifest a red-shift with increasing x from 5 to 45. The Aux/BaTiO3 composite film with the optimal SPR effect (x = 35) exhibits the highest photocatalytic activity for the degradation of Rhodamine B (RhB) aqueous solution among all films under whole spectrum sunlight irradiation.