Fabrication of Bi(2)MoO(6) Nanosheets/TiO(2) Nanorod Arrays Heterostructures for Enhanced Photocatalytic Performance under Visible-Light Irradiation

Bi(2)MoO(6)/TiO(2) heterostructures (HSs) were synthesized in the present study by growing Bi(2)MoO(6) nanosheets on vertically aligned TiO(2) nanorod arrays using a two-step solvothermal method. Their morphology and structure were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Excellent visible-light absorption was observed by UV–Vis absorption spectroscopy, which was attributed to the presence of the Bi(2)MoO(6) nanosheets with a narrow-band-gap. The specific surface area and pore volume of the photocatalysts were significantly increased due to the hierarchical structure composed of Bi(2)MoO(6) nanosheets and TiO(2) nanorods. The photoluminescence and photoelectrochemical characterizations showed improved separation and collection efficiency of the Bi(2)MoO(6)/TiO(2) HSs towards the interface charge carrier. The photocatalytic analysis of the Bi(2)MoO(6)/TiO(2) HSs demonstrated a significantly better methylene blue (MB) degradation efficiency of 95% within 3 h than pristine TiO(2) nanorod arrays under visible-light irradiation. After three photocatalytic cycles, the degradation rate remained at ~90%. The improved performance of the Bi(2)MoO(6)/TiO(2) HSs was attributed to the synergy among the extended absorption of visible light; the large, specific surface area of the hierarchical structure; and the enhanced separation efficiency of the photogenerated electron-hole pairs. Finally, we also established the Bi(2)MoO(6)/TiO(2) HSs band structure and described the photocatalytic dye degradation mechanism. The related electrochemical analysis and free-radical trapping experiments indicated that h(+), ·O(2)(−) and ·OH have significant effects on the degradation process.