Milling‐Induced Synthesis of BiOCl1‐xBrx Solid Solution and Their Adsorptive and Photocatalytic Performance

CH ₃COO (BiO) (denoted as BiOA c) is one of the most easily obtained bismuth compounds and was for the first time proposed by our group as an effective UV light photocatalyst. Herein, BiOC l_1‐x B r_x (x refers to the feeding atomic ratio) were obtained using a facile solid state milling and subsequent water washing. More importantly, all of the as‐prepared BiOC l_1‐x B r_x possessed better visible light photocatalytic activity to the corresponding ones obtained by previously reported solution route. Especially at an optimal x value of 0.5, the solid solution showed the highest photodegradation efficiency (~100%) for rhodamine B (RhB) with a concentration of 30 mg L⁻¹, whereas the degradation efficiency was only 63% over that obtained by solution route. Furthermore, the as‐prepared BiOC l_0.5Br_0.5 also exhibited excellent photodegradation activity for malachite green (MG ). The superior photocatalytic performance of the as‐prepared BiOC l_0.5Br_0.5 could be attributed to its thinner sheetlike structures and highly exposed (001) facets, which enable effective separation of the photogenerated electrons and holes along the 001] direction. In addition, the as‐prepared BiOC l_0.5Br_0.5 revealed dramatic adsorption capacity for cationic dyes like MG , RhB and methylene violet (MV ), as well as anion (Cr₂O₇)²⁻ owing to electrostatic interaction between cationic dyes and negatively charged surface of BiOC l_0.5Br_0.5, and positively charged surface in K₂Cr₂O₇ solution (pH ≈ 3).