Modified Bi₂WO₆ with metal-organic frameworks for enhanced photocatalytic activity under visible light

Bi₂WO₆/MIL-100(Fe) heterostructures with visible light response have been synthesized for the first time through a facile hydrothermal method. The as-synthesized Bi₂WO₆/MIL-100(Fe) nanocomposites were characterized using the powder X-ray diffraction, high resolution transmission electron microscopy, scanning electron microscopy, UV-vis diffuse reflectance spectra, and N₂ adsorption-desorption techniques, respectively. The composition of Bi₂WO₆/MIL-100(Fe) nanocomposites has been varied and the performance was evaluated by photodegrading salicylic acid under visible-light irradiation. It is found that the MIL-100(Fe)-Bi₂WO₆ systems exhibit much higher photocatalytic activity than pure Bi₂WO₆ and MIL-100(Fe). The enhanced photocatalytic performance of Bi₂WO₆/MIL-100(Fe) heterostructures may be ascribed to the formation of p-n heterojunctions between Bi₂WO₆ and MIL-100(Fe), which result in the effective separation of charge carriers. After 5-time recycling for the photodegradation of salicylic acid, there was not significant decrease in the photocatalytic activity, implying that the as-prepared photocatalysts are highly stable.