Photocatalytic activity enhancement of Bi₂WO₆ nanoparticles by Ag doping and Ag nanoparticles modification

Bi₂WO₆ nanoparticles doped with Ag, and modified with Ag nanoparticles, were successfully prepared using a two-step microwave assisted and hydrothermal synthesis. With Ag doping, the Bi ions were substituted by the dopant Ag ions in the host lattice structure of Bi₂WO₆. With Ag nanoparticles modification, the Ag nanoparticles grew on the surface of the Bi₂WO₆ nanoparticles without changing the host lattice structure. The photocatalytic activities of the samples were studied by visible light irradiation of rhodamine B. Both the Ag doping and the Ag nanoparticles modification enhanced the photocatalytic activity of the Bi₂WO₆ nanoparticles. Moreover, Ag nanoparticles modification produced a more than two times higher enhancement of the photocatalytic activity than the Ag doping method. Furthermore, a mechanism of the significant photocatalytic activity enhancement by Ag nanoparticles modification is proposed.