Synthesis and characterization of CeO2/g-C3N4 composites with enhanced visible-light photocatatalytic activity

Cerium dioxide/graphitic carbon nitride (CeO2/g-C3N4) visible-light-induced photocatalysts were successfully prepared by a simple mixing-calcination technique. The CeO2/g-C3N4 nanocomposites were characterized by thermogravimetric analysis (TG), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflection spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and the photocurrent-time (PT) measurements. Photocatalytic activities of the prepared samples were examined by studying the degradation of methylene blue (MB) and 4-chlorophenol (4-CP) under visible light irradiation (>400 nm). The CeO2/g-C3N4 composites showed higher photocatalytic activity than that of CeO2 and g-C3N4. The optimum photoactivity of CeO2/g-C3N4 (13.0%) exhibited the highest photocatalytic activity in pollutant treatment and an enhanced photocurrent under visible light. These enhanced activities could be attributed to the synergetic effect between g-C3N4 and CeO2. The increasing photocatalytic activity mechanism was also discussed.