Facile synthesis of flake-like Bi2WO6/carbon fiber heterojunction catalysts with enhanced photoactivity under visible light illumination

Novel carbon fiber based Bi2WO6(Bi2WO6/CF) photocatalysts were facilely prepared by hydrothermal method and used to catalytically degrade Orange II azo-dye in water. The catalysts were characterized by X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Fourier transfer infrared (FTIR), Raman and UV-vis. SEM images revealed that Bi2WO6 nanoflakes dispersed over the carbon fiber surface have sizes in the range of 160-500 nm. The heterojunction Bi2WO6/CF catalyst showed stronger absorption in the visible light region where lower band gap of 2.6 eV was achieved. The original structure with flakes of Bi2WO6 deposited exclusively on the surface of carbon fibers, exhibited enhanced the photocatalytic activity under UV-A and visible light illumination. The decoration of CF with Bi2WO6 nanoflakes likely promoted the dye adsorption on the photocatalyst via n- n electron coupling and also accelerated the charge transfer and promoted the separation of photo-excited electron/hole pairs.