A Facile Strategy to Prepare Zr4+-Modified Bi₂WO6 with Enhanced Visible-Light Photocatalytic Activities.

Abstract

A series of Zr4+-modified Bi2WO6 photocatalysts were synthesized using a hydrothermal method employing Bi(NO3)3·5H2O, Na2WO4·2H2O and Zr(NO3)4 as precursors. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV-vis absorption spectroscopy (UV-vis) and photoluminescence spectroscopy (PL). The investigations indicated that the flower-like Bi2WO6 3D structures were constructed from a large number of 2D layers of interconnected nanoplates. The energy gaps of Zr4+-modified Bi2WO6 decreased compared with that of pure Bi2WO6. In addition, fluorescence quenching was observed because the recombination of charge carriers was effectively suppressed by Zr4+. The photocatalytic properties of samples were evaluated by the degradation of Rhodamine B (RhB) solution under visible-light irradiation. The results indicate that the 1.0 mol% Zr4+-modified Bi2WO6 possesses obviously enhanced photocatalytic activity, showing the great potential for wastewater purification. In addition, a tentative photocatalytic mechanism is proposed to understand the experimental results over the Zr4+-modified Bi2WO6 photocatalysts.