A series of BiOBr nanosheets with tunable exposing proportion of (010) facets had been synthesized. In the synthesis process, different n-alcohols are used, which not only promote the exposure of (010) facets, but also modulate the size and thickness of these BiOBr nanosheets in a wide range. Furthermore, these nanosheets showed an efficient photodegradation activity for salicylic acid (SA) and Rhodamine B (RhB). By comparison, the sample prepared in n-hexanol possessed the highest photocatalytic activity than those synthesized in n-butanol and methanol, respectively. This excellent photocatalytic activity was attributed to the thin lamellar thickness and the exposure of (010) facets, which facilitated the separation of photoinduced electrons and holes.