Fabrication of one dimensional hierarchical WO3/BiOI heterojunctions with enhanced visible light activity for degradation of pollutants

One-dimensional (1D) hierarchical WO3/BiOI p-n (WB) heterojunctions with different mass percentages of WO3 were fabricated through a precipitation process. Various analytical techniques were employed to characterize the resulting WB composites, and their photocatalytic properties were measured by the degradation of rhodamine B (RhB) and methylene blue (MB) under irradiation of visible light. The WB heterojunctions showed largely enhanced photocatalytic performance as compared to the pure photocatalysts. Notably, the degradation rate constant of RhB by WB-10 was 3.3 and 33.6 times higher than those of pure BiOI and WO3, respectively. The enhanced activity could be attributed to the hierarchical p-n heterostructures, which can supply more reaction sites and effectively promote the separation of photogenerated charge carriers, as confirmed by PL and photocurrent. Trapping experiments implied that holes (h(+)) and superoxide anion radicals (O-2(-)) were the dominant active species for organic pollutants decomposition on the WB composites. This work may benefit the construction of hierarchical heterostructures with high photocatalytic efficiency.

Automated summary

Hierarchical WO3/BiOI p-n heterojunctions with different mass percentages of WO3 were fabricated, showing significantly enhanced photocatalytic performance compared to pure photocatalysts under visible light irradiation. The enhanced activity was attributed to the hierarchical p-n heterostructures providing more reaction sites and promoting the separation of photogenerated charge carriers.