Design of high-efficiency visible light photocatalysts is critical in the degradation of antibiotic pollutants in water, a key step towards environmental remediation. In the present study, Mo-doped BiOBr nanocomposites are prepared hydrothermally at different feed ratios, and display remarkable visible light photocatalytic activity towards the degradation of sulfanilamide, a common antibacterial drug. Among the series, the sample with 2% Mo dopants exhibits the best photocatalytic activity, with a performance 2.3 times better that of undoped BiOBr. This is attributed to Mo doping that narrows the band gap of BiOBr and enhances absorption in the visible region. Additional contributions arise from the unique materials morphology, where the highly exposed (102) crystal planes enrich the photocatalytic active sites, and facilitate the adsorption of sulfanilamide molecules and their eventual attack by free radicals. The reaction mechanism and pathways are then unraveled based on theoretical calculations of the Fukui index and liquid chromatography/mass spectrometry measurements of the reaction intermediates and products. Results from this study indicate that deliberate structural engineering based on heteroatom doping and morphological control may serve as an effective strategy in the design of highly active photocatalysts towards antibiotic degradation.

高效可见光光催化剂的设计对于水中抗生素污染物的降解至关重要，这是环境修复的关键一步。在本研究中，Mo掺杂的BiOBr纳米复合材料以不同的进料比水热制备，对常见的抗菌药物磺胺的降解表现出显着的可见光光催化活性。在该系列中，Mo掺杂量为2%的样品表现出最好的光催化活性，其性能是未掺杂BiOBr的2.3倍。这归因于 Mo 掺杂缩小了 BiOBr 的带隙并增强了可见光区域的吸收。其他贡献来自独特的材料形态，其中高度暴露的（102）晶面丰富了光催化活性位点，促进磺胺分子的吸附和自由基的最终攻击。然后基于福井指数的理论计算和反应中间体和产物的液相色谱/质谱测量来揭示反应机理和途径。这项研究的结果表明，基于杂原子掺杂和形态控制的精心结构工程可以作为设计用于抗生素降解的高活性光催化剂的有效策略。