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, N2 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 •O2– are the main active species in the photocatalytic oxidation of RhB solution in the presence of DyVO4/g-C3N4 composite.