Enhanced visible-light-driven Pd/Bi2WO6 heterojunctions used for photodegradation of rhodamine B

Abstract

Heterostructure Pd/Bi2WO6 nanocomposites as visible-light-driven photocatalyst used for degradation of rhodamine B (RhB) were prepared by a sonochemical-assisted deposition method. Phase, morphology, atomic vibration mode, oxidation state of element and optical properties of pure Bi2WO6 and heterostructure Pd/Bi2WO6 nanocomposites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, Fast-Fourier-Transform electron diffraction and X-ray photoelectron spectroscopy. The analyses showed a mixed phase of face-centered cubic Pd structure as a minor phase and orthorhombic Bi2WO6 structure as a major phase with Pd nanoparticles supported on top of Bi2WO6 nanoplates. The photocatalytic performance of Bi2WO6 and Pd/Bi2WO6 was tested through photodegradation of rhodamine B (RhB) under visible light irradiation. In this research, the loaded Pd nanoparticles greatly increased the photodegradation of RhB under visible light irradiation. Heterostructure 10% Pd/Bi2WO6 nanocomposites showed the highest photocatalytic activity for RhB degradation under visible light irradiation because of the formation of Schottky barriers and promotion of interfacial charge-transfer kinetics between metallic nanoparticles and semiconducting nanoplates.