Synthesis, Characterization, and Activity Evaluation of DyVO4/g-C3N4 Composites under Visible-Light Irradiation

DyVO4/graphitic carbon nitride (DyVO4/g-C3N4) composite photocatalyst with visible-light response was prepared by a milling and heating treatment method. The synthesized powder was characterized by X-ray diffraction, thermogravimetry/differential thermal analysis, N-2 adsorption, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV-vis diffuse reflection spectroscopy. The activity of composite photocatalyst DyVO4/g-C3N4 for photodegradation of rhodamine B is much higher than that of either single-phase g-C3N4 or DyVO4. The obviously increased performance of DyVO4/g-C3N4 is mainly ascribed to the electron-hole separation enhancement at the interface of the two semiconductors, as proven by photoluminescence spectroscopy and photocurrent measurement In addition, it is found that holes and O-center dot(2)- are the main active species in the photocatalytic oxidation of RhB solution in the presence of DyVO4/g-C3N4 composite.