The ZnS-Bi-TiO 2 composites were prepared by the sol-gel method and were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). It is found that the doped Bi as Bi 4+ /Bi 3+ species existed in composites, and the introducing of ZnS enhanced further the light absorption ability of TiO 2 in visible region and reduced the recombination of photogenerated electrons and holes. As compared to pure TiO 2 , the ZnS-Bi-TiO 2 exhibited enhanced photodegradation efficiency under xenon lamp irradiation, and the kinetic constant of methyl orange removal with ZnS-Bi-Ti-0.005 (0.0141 min −1 ) was 3.9 times greater than that of pure TiO 2 (0.0029 min −1 ), which could be attributed to the existence of Bi 4+ /Bi 3+ species, the ZnS/TiO 2 heterostructure
