Synthesis of novel and stable g-C3N4-Bi2WO6 hybrid nanocomposites and their enhanced photocatalytic activity under visible light irradiation

Graphitic carbon nitride (g-C3N4) nanosheets with a thickness of only a few nanometres were obtained by a facile deammoniation treatment of bulk g-C3N4 and were further hybridized with Bi2WO6 nanoparticles on the surface via a solvothermal method. The composite photocatalysts were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV–vis diffuse reflection spectroscopy and X-ray photoelectron spectroscopy (XPS). The HR-TEM results show that the nano-sized Bi2WO6 particles were finely distributed on g-C3N4 sheet surface, which forms heterojunction structure. The UV–vis diffuse reflectance spectra (DRS) show that the absorption edge of composite photocatalysts shifts towards lower energy region in comparison with those of pure g-C3N4 and Bi2WO6. The degradation of methyl orange (MO) tests reveals that the optimum activity of 8 : 2 g-C3N4-Bi2WO6 photocatalyst is almost 2.7 and 8.5 times higher than those of individual g-C3N4 and Bi2WO6. Moreover, the re...