Room temperature synthesis of one-dimensional hierarchical hollow BiOBr with tunable photocatalysis reaction pathway for RhB under visible light.

One-dimensional (1D) hierarchical photocatalyst has the advantages of 1D materials and hierarchical materials, which is a kind of potential high performance photocatalytic materials. However, how to efficiently synthesize 1D hierarchical BiOBr is still a huge challenge. Herein, 1D rod-like BiO(OH)(NO)·3HO, the hydrolysis product of Bi(NO)·5HO, was acted as both the template and Bi source to synthesize 1D hierarchical hollow BiOBr (1DHHBr) through a facile solution stirring method at room temperature, using KBr as Br source. As compared with lamellar-like BiOBr, 1DHHBr has larger specific surface areas and abundant mesoporous pores. The superiorities of morphology and texture for 1DHHBr not only improve the adsorption capability for RhB molecules, but also raise the separation efficiency of photogenerated charges. Therefore, 1DHHBr exhibits much higher photocatalytic degradation performance of RhB under visible light through an initial N-deethylation process followed by the disruption conjugated chromophore groups pathway, based on the combination of photocatalytic mechanism of 1DHHBr and photosensitization mechanism of RhB. The active species trapping tests prove that •O is the major active species for the N-deethylation of RhB, while h is the main active species for the cleavage of conjugated chromophore structures of RhB and its deethylated derivatives. Importantly, the visible light photocatalysis reaction pathway for RhB over 1DHHBr can be tuned by the addition of benzoquinone and sodium oxalate, respectively. Moreover, this facile approach can be easily expanded to fabricate other 1D hierarchical hollow BiOX (e.g., BiOCl and BiOI) and therefore justify its usefulness in rationally designing the 1D hierarchical hollow bismuth-based layered photocatalysts.