Preparation of upconversion Yb3+ doped microspherical BiOI with promoted photocatalytic performance

Bismuth oxychloride (BiOI) has a good visible light responsive property due to their relatively narrow band gap, and its photocatalytic performance was further improved by doping ytterbium ions (Yb3+). This may be due to strong optical absorption in UV–visible light, effective separation of the photoinduced electron-hole pairs, and the capacity to up-convert Near-IR light into visible-light of Yb3+ ions. In this study, a facile solvothermal method was adopted to synthesize Yb3+ ions doped BiOI photocatalysts. The doped photocatalysts with molar ratios of 0, 0.5, 1, 1.5, 2 and 2.5% Yb3+ ions were prepared. The 2% Yb3+ ions doped BiOI exhibited the highest photocatalytic degradation efficiency on degrading Rhodamine B, which was two times higher than that of pure BiOI. Also Yb3+ ions doped BiOI showed high photocatalytic degradation on herbicide isoproturon. The prepared photocatalysts were characterized by SEM, XRD, UV–vis DRS. It indicated that the doping ions entered the lattice of BiOI crystals and improved the photocatalytic performance. The photocatalytic mechanism was also studied. This work provided the potential application of Yb3+ doped BiOI for the degradation of organic contaminants.