The staggered heterojunction of CeO2/CdS nanocomposite for enhanced photocatalytic activity

To modify the photocatalytic activity of CeO2, CdS nanoparticles was composited with CeO2 through a homogeneous precipitation method. The crystal structure, composition, morphology, and optical properties of CdS/CeO2 composite were analyzed in detail. The results found that CdS/CeO2 composite consisted of the cubic fluorite structure of CeO2 and wurtzite hexagonal structure of CdS. Meanwhile, TEM magnification of CdS/CeO2 composite exhibited clear lattice fringe corresponding to [hkl] plane of CeO2 and CdS. UV–visible absorption spectra showed that CdS extended the adsorption edge of the CdS/CeO2 composite to longer visible region, which related to the decrease of band gap. The coexistence of staggered type II band alignment in the CdS/CeO2 composite facilitated the charge separation of visible–excited electrons and holes, thereby decreasing the recombination and improving the efficient photocatalytic activity for methylene blue dye degradation, with the apparent rate constant (0.0102 min−1) which is about 7 times higher than that of pure CeO2 (k = 0.0014 min−1). [Display omitted] •The CeO2/CdS heterojunction was simply prepared by homogeneous precipitation method.•The presence of CdS improved light-harvesting ability of the materials in visible region.•The CeO2/CdS nanocomposite showed 7-fold enhancement in photocatalytic activity compared with the unmodified CeO2.