Synthesis and behaviors of g-C 3 N 4 coupled with La x Co 3-x O 4 nanocomposite for improved photocatalytic activeity and stability under visible light

Abstract Novel LaxCo3-xO4 doped graphitic carbon nitride photocatalysts were synthesized via a microwave-assisted hydrothermal method. The rate of H2 production varies with the ratio of the La/Co doped on g-C3N4, the highest hydrogen production activity is 63.12 μmol h−1 when the molar ratio of La/Co is 10% in the nanohybrid. The nanohybrid photocatalyst exhibited activity for hydrogen generation is higher than that of pure g-C3N4 by up to 6 times under visible light irradiation. The synergistic effect of g-C3N4 and LaxCo3-xO4 leads to efficient separation of the photogenerated charge carriers, as a result of enhances the visible light photocatalytic hydrogen production activity of the photocatalysts. The effective coupling of LaxCo3-xO4 on g-C3N4 can efficiently extend the light absorption of the g-C3N4 to visible region and enhance the charge separation efficiency of g-C3N4/LaxCo3-xO4 composites. The possible photocatalytic mechanism of the g-C3N4/LaxCo3-xO4 photocatalysts is inferred by XPS, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), and electrochemical workstation.