LAUSR

Abstract In this report, Bi 2 WO 6 -Bi composite was prepared through an in situ photoreduction method and was characterized systematically by X-Ray diffraction, transmission electron microscopy, X-Ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The as-prepared Bi 2 WO 6 -Bi maintains the same crystal structure with the pristine Bi 2 WO 6 regardless of some surface defects. Nevertheless, these surface defects result in the change of surface oxygen adsorption mode from hydroxyl to molecular oxygen on Bi 2 WO 6 . Photocatalytic activity over Bi 2 WO 6 -Bi is 2.4 times higher than that of Bi 2 WO 6 towards the degradation of organic dye Rhodamine B (RhB) under visible light irradiation (λ > 420 nm). A deep study shows that cleavage of benzene ring is the main pathway for RhB degradation over Bi 2 WO 6 , but both the benzene cleavage and de-ethylation pathway coexist for RhB decomposition in the presence of Bi 2 WO 6 -Bi as the photocatalyst. Photoelectrochemical study including transient photocurrent tests and electrochemical impedance spectroscopy measurements shows that Bi 2 WO 6 -Bi could facilitate the charge transfer process compared to Bi 2 WO 6 . These data above has indicated a new insight into the promotion mechanism based on Bi related heterostructures.