Hierarchical Bi-doped BiOBr microspheres assembled from nanosheets with (0 0 1) facet exposed via crystal facet engineering toward highly efficient visible light photocatalysis

•Firstly report of Bi/BiOBr microspheres with dominant exposed (0 0 1) facets.•Superior performance of Bi/BiOBr-001-m over other BiOBr catalysts.•Synergistic effect of crystal structures engineering and doped Bi element.•Sensitization effect of adsorbed RhB for bettering photocatalyst property.