Fabrication of BiOIO3 with induced oxygen vacancies for efficient separation of the electron-hole pairs

Bismuth-based nanomaterials exhibiting unique structures, which endow them with fascinating physicochemical properties, have received more and more interests as promising photocatalysts. Fabrication of BiOIO3 photocatalysts by calcination method was investigated for the first time. XRD patterns showed that the crystallinity of BiOIO3 photocatalysts could be controlled by calcination temperature. TGA demonstrated that calcining the precursor at a specific temperature range was appropriate for preparing BiOIO3 photocatalysts. XPS and FT-IR characterization revealed that the BiOIO3 photocatalysts prepared by calcination method possessed oxygen vacancies, which acted as the positive charge centers to trap the electron easily, inhibiting the recombination of photo electron-hole pairs. Furthermore, PL spectra confirmed the oxygen vacancies can favor for the separation of the electron-hole pairs and in turn enhance the photocatalytic performance. From the above analysis, the mechanism of preparing BiOIO3 photocatalysts by calcination method was proposed. Meanwhile, the effect of oxygen vacancies on the photocatalytic activity of BiOIO3 photocatalysts was investigated. The BiOIO3 photocatalysts with oxygen vacancies were found to be efficiently photocatalytically remove gaseous Hg0 and the relative photocatalysis mechanism was investigated.