Constructing surface oxygen vacancy in the [Bi2O2]2+ layer defects mediated Bi2MoO6 enhanced visible light responsive photocatalytic activity

Bi2MoO6 nanospheres with surface oxygen vacancies (SOVs) controlled by the calcination process were prepared in this study. Performance testing revealed that the Bi2MoO6-4 sample (Bi2MoO6 calcined at 350 degrees C for 4 h) with SOVs achieved a remarkable photocatalytic degradation efficiency up to 99.16% for Rhodamine B (RhB) within 50 min, which is 2.19 times higher than that of pure Bi2MoO6. The higher photocatalytic performance of the Bi2MoO6-4 sample is attributed to the SOVs' defect level located at the Bi2MoO6 bandgap, narrowing the bandgap to effectively promote the photogenerated charge separation. The promotion of photocarrier separation and electron were transferred due to the Bi-O bond breakage in the Bi2MoO6-4 [Bi2O2](2+) layer, which mediates the defect level of SOVs in the band structure. The density functional theory calculation results reveal the possible formation site of the oxygen vacancy and the vacancy-induced defect states. This study provides a new approach for fabricating new photocatalysts with surface oxygen defects.