Hierarchical Bi-doped BiOBr microspheres assembled from nanosheets with (001) facet exposed via crystal facet engineering toward highly efficient visible light photocatalysis

A facile one-step solvothermal process was used to synthesize Bi-doped BiOBr microspheres with mainly the (0 0 1) crystal facet exposed (Bi/BiOBr-001-m), which exhibited enhanced photocatalytic performance. The photocatalytic performance and stability of the obtained Bi/BiOBr-001-m photocatalyst for Cr(VI) photoreduction removal and rhodamine B (RhB) photooxidation degradation were significantly better than those of pure BiOBr and Bi-doped BiOBr microspheres. The enhanced performance is ascribed to the retarding effect of photoinduced electron-hole recombination caused by Bi doping and the predominant (0 0 1) crystal plane composite structure. The photocatalytic performance could be further boosted by the adsorbed RhB owing to the dye sensitization effect. This work provides a reference for effectively improving the photocatalytic performance by combining crystal facet engineering and element doping.