Iodine-vacancy BiOI1-x ultrathin sheets for improved visible-light photooxidation activities

Abstract Band and surface structures are closely related to photocatalytic activities of semiconductor materials and can be adjusted via vacancy introduction. BiOI nanosheets are widely developed in the photocatalytic field due to their wide visible-light absorption band and sheet-like structure. However, the low photooxidative capability of such nanosheets considerably restricts their application. In our study, a novel strategy using glycerin was developed to construct I vacancies in BiOI. Surface band structure was modified by glycerin to achieve enhanced photooxidative activity. The valence band maximum (VBM) position of I-vacancy BiOI1-x ultrathin nanosheets was promoted to 1.51 eV via introducing I vacancies. I- vacancy BiOI1-x ultrathin sheets exhibited substantially improved visible-light photooxidation capacity in degrading methyl orange and phenol due to the positive VBM position, shortened carrier transport distance, and suitable surface atom structure. Results demonstrate a new strategy of constructing vacancy defects in photocatalysts.