Carbon-Doped ZnO Hybridized Homogeneously with Graphitic Carbon Nitride Nanocomposites for Photocatalysis

The nanocomposite photocatalysts of carbon-doped zinc oxide (ZnO) hybridized with graphitic carbon nitride (g-C3N4) were prepared through simple one-step calcination of evaporation-dried mixture of dicyandiamide and zinc nitrate. Compared with pure ZnO and g-C3N4, the absorption of the prepared g-C3N4/ZnO nanocomposites shifted toward lower energy region, and the broader and stronger absorbance in the visible light region was observed, which was related to the content of g-C3N4 in the nanocomposites. The photocatalytic activities of the resultant g-C3N4/ZnO nanocomposites for the degradation of methylene blue (MB) dye under visible light irradiation were enhanced remarkably and much higher than that of g-C3N4. The optimal content of g-C3N4 in the prepared nanocomposites was found at a weight percent of 50.7%, which corresponded to the homogeneous hybridization between ZnO and g-C3N4. The improved photocatalytic performance of the g-C3N4/ZnO nanocomposites was ascribed to the elevation of the separation efficiency of photoinduced electron-hole pairs, resulting from the heterojunction established between the interfaces of g-C3N4 and ZnO.