Fabrication and photocatalytic performance of WO3/TiO2 heterojunction composites

The rutile TiO2 microspheres and WO3 nanosheets were both synthesized via the hydrothermal treatment and the type-II WO3/TiO2 heterojunction with different mass ratios (1:2, 1:5, and 1:8) was prepared by a simple physical mixing method. The photocatalytic performance of the photocatalysts was investigated by the degradation of Rhodamine B (RhB) dye under simulated sunlight irradiation. Compare with pure TiO2 and WO3, the WO3/TiO2 with a mass ratio of 1:5 exhibited the highest photocatalytic efficiency of 91.5% within 60 min. The active species trapping experiment revealed that holes (h+) and superoxide radical (·O2−) played main roles in the degradation process. The unique type-II WO3/TiO2 heterojunction not only extended the light absorption range, but also promoted charge carriers transfer and separation, leading to the enhancement of photocatalytic activity.