Fabrication of ZnO/g-C₃N₄ nanocomposites for enhanced visible light driven photocatalytic activity

ZnO/g-C₃N₄ nanocomposite photocatalysts were prepared using a simple and cost-effective pyrolysis method. The structural, optical, surface morphological and photocatalytic properties of the nanocomposites were analyzed and compared with those of g-C₃N₄. X-ray diffraction results revealed that all the ZnO/g-C₃N₄ samples have a hexagonal wurtzite phase of ZnO. Spectroscopic results obtained via FT-IR technique were consistent with the layered structure of sp² hybridized bonding features of C and N in g-C₃N₄, besides Zn–O stretching vibrations. Photoluminescence results revealed that ZnO hybridization with g-C₃N₄ showed efficient separation and delayed recombination of photoinduced electron–hole pairs. TEM analysis clearly displayed that ZnO nanoparticles are anchored on g-C₃N₄ and showed the interface between the ZnO and g-C₃N₄. The ZnO/g-C₃N₄ nanocomposites exhibited enhanced visible light photocatalytic degradation against methylene blue dye when compared to g-C₃N₄. A plausible mechanism has been proposed for the observed enhanced photocatalytic activity. (paper)