Graphene-analogue BN-modified microspherical BiOI photocatalysts driven by visible light.

Novel hierarchical microspherical BiOI photocatalysts modified by graphene-analogue BN were prepared by a facile one-pot solvo-thermal method. Rhodamine B, methylene blue and 4-chlorophenol were used as target pollutants to evaluate the photocatalytic performance of the BN/BiOI composites under visible light irradiation. The experimental results indicated that the BN/BiOI composites exhibited a significantly enhanced photocatalytic activity compared with pure BiOI and P25 TiO2. The optimum photocatalytic activity was achieved when the BN content was 0.5 wt%. The improved photodegradation efficiency was mainly attributed to the extended light absorption range, larger specific surface area and increased separation rate of the photogenerated electron-hole pairs. The radical trapping experiments demonstrated that h(+) and ˙O2(-) radicals were the dominant active species, whereas the ˙OH radicals could be neglected. A possible photocatalytic mechanism is proposed. The strategy presented here provides an ideal platform for the design of other graphene-analogue BN-modified microspherical composite photocatalysts for broad applications in the field of photocatalysis.