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

Abstract

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.