Heterostructured Bi2O3/Bi2MoO6 nanocomposites: simple construction and enhanced visible-light photocatalytic performance

Heterostructured Bi2O3/Bi2MoO6 nanocomposites with enhanced visible-light photocatalytic activity are successfully constructed by a simple two-step route, employing bismuth nitrate and sodium molybdate as the main raw materials in the presence of polyvinyl pyrrolidone (PVP). The phase and the morphology of the as-prepared composites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), (high-resolution) transmission electron microscopy (TEM/HRTEM), and energy dispersive spectrometry (EDS). It is found that heterostructured Bi2O3/Bi2MoO6 nanocomposites exhibit stronger catalytic activities for the degradation of Rhodamine B (RhB) and 2,4-dinitrophenol (2,4-DNP) under the irradiation of visible light than the single component (Bi2O3 or Bi2MoO6). The above enhanced photocatalytic performance should be attributed to the formation of the p-n junction between the p-type Bi2O3 and n-type Bi2MoO6, which effectively halts the fast recombination of photogenerated electrons and holes. Moreover, the as-obtained Bi2O3/Bi2MoO6 nano-heterostructures also display improved photoelectochemistry performance and high photochemical stability, which is important for conquering the photo-corrosion of photocatalysts. Also, the present work is a useful attempt for the design of new visible-light photocatalytic materials with heterojunction structures.