Preparation, characterization and photocatalytic performance of g-C3N4/Bi2WO6 composites for methyl orange degradation

Abstract The g-C 3 N 4 /Bi 2 WO 6 composites have been synthesized and used as photocatalysts for degradation of methyl orange (MO) dye. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR), UV–visible diffuse reflection spectroscopy (DRS), and N 2 physisorption isotherms were used to characterize the physicochemical properties of the materials. With the increase of hydrothermal time, the morphology of Bi 2 WO 6 evolved from nanoparticles to microplates, flower-like and helix/tyre-like superstructures; in the meanwhile the g-C 3 N 4 component was gradually dissolved. Such obtained g-C 3 N 4 /Bi 2 WO 6 composites showed optical band gap in the range of 2.67–2.75 eV. Photocatalytic results showed that g-C 3 N 4 /Bi 2 WO 6 composites are more active than either pure Bi 2 WO 6 or g-C 3 N 4 , and the weight ratio of g-C 3 N 4 to Bi 2 WO 6 and the hydrothermal time significantly affected the degradation efficiency of the materials. The optimum weight ratio of g-C 3 N 4 to Bi 2 WO 6 was 0.5:1, and that for hydrothermal time was 6 h at 160 °C.