Enhanced photocatalytic activity of Bi2WO6 loaded with Ag nanoparticles under visible light irradiation

Ag-loaded Bi2WO6 nanoparticles were prepared via a facile alcohol-thermal process in ethylene alcohol system. The products were characterized by XRD, TEM, HRTEM and energy-dispersed X-ray (EDX) microanalysis. The results revealed that it was the metallic Ag deposited on Bi2WO6, which was further confirmed by the surface plasmon absorption band existed in the UV-vis absorption spectrum. Compared with pure Bi2WO6, Ag-loaded Bi2WO6 photocatalysts exhibited significantly enhanced photocatalytic activity in inactivating E. call, a Gram-negative bacterium, and S. epidermidis, a Gram-positive bacterium under visible light irradiation (lambda > 420 nm). The influence of the content of silver on the catalytic activity of Bi2WO6 photocatalyst has been investigated. The results concerning the effect of silver on the catalytic activity of Bi2WO6 photocatalyst revealed that the significant enhancement of photocatalytic activity can be attributed to the synergetic effects between noble metal and semiconductor component. (C) 2009 Elsevier B.V. All rights reserved.