SPR effect of bismuth enhanced visible photoreactivity of Bi2WO6 for NO abatement

Abstract Bi 2 WO 6 is a typical visible-light-responsive semiconductor photocatalyst with a layered structure. However, the relatively large bandgap (2.6–2.8 eV) and quick recombination of photo-generated carriers result in its low quantum efficiency. In this paper, Bi-nanospheres-modified flower-like Bi 2 WO 6 was successfully prepared by solvothermal treatment of Bi 2 WO 6 powders in Bi(NO 3 ) 3 solution using ethylene glycol as reductant. The photoreactivity of this photocatalyst was evaluated by the oxidation of NO in a continuous-flow reactor under irradiation by a visible LED lamp ( λ > 400 nm). It was found that both Bi nanospheres and flower-like Bi 2 WO 6 precursor exhibit very poor photocatalytic activity with NO removal rates of only 7.7% and 8.6%, respectively. The photoreactivity of Bi/Bi 2 WO 6 was found to steadily increase from 12.3% to 53.1% with increase in the amount of Bi nanospheres from 0 to 10 wt%. However, with further increase in the loading amount of Bi nanospheres, the photoreactivity of Bi/Bi 2 WO 6 hybridized photocatalyst begins to decrease, possibly due to the light filtering by the Bi nanospheres. The enhanced visible photoreactivity of Bi/Bi 2 WO 6 towards NO abatement was attributed to surface plasmon resonance driven interfacial charge separation. The excellent stability of Bi/Bi 2 WO 6 hybridized photocatalyst towards NO oxidation demonstrates its potential for applications such as air purification.