A series of flower-like BiOBr with exposed the (0 0 1) and (0 1 0) facets were successfully synthesized by pH adjustment method for gas-phase Hg⁰ photocatalytic oxidation. The physicochemical properties of the BiOBr were characterized by XRD, SEM, TEM, SAED, XPS, UV–vis DRS, PL, EIS and ESR analysis. It was found that BiOBr with the main exposed (0 1 0) facets exhibited better photocatalytic activity, and its best efficiency reached 65%. This can be attributed to the optimal ratio of dominant (0 1 0) facets exposed by pH adjustment to effectively promote the spatial separation of photo-generated charges. Finally, a possible photocatalytic reaction mechanism was proposed.

通过pH调节法成功合成了一系列暴露于（0 0 1）和（0 1 0）面的花状BiOBr，用于气相Hg ⁰光催化氧化。通过XRD，SEM，TEM，SAED，XPS，UV-vis DRS，PL，EIS和ESR分析对BiOBr的理化性质进行了表征。发现具有主要暴露面（0 1 0）的BiOBr表现出更好的光催化活性，其最佳效率达到65％。这可以归因于通过调节pH值曝光以有效促进光生电荷空间分离的最佳（0 1 0）刻面比例。最后，提出了一种可能的光催化反应机理。