Abstract A new kind of BiOBr-Bi composite with improved photocatalytic capabilities was successfully prepared by in-situ reduction. The X-ray diffraction (XRD), Scanning electron microscopy (SEM), Ultraviolet–visible spectroscopy (UV–VisDRS), X-ray photoelectron spectroscopy (XPS), Brunner-Emmet-Teller measurements (BET), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) and the electron paramagnetic resonance (EPR) were used to characterize the morphological structures, physical properties and surface element composition of the photocatalysts. In addition, photocatalytic activity was evaluated by degrading the antibiotic norfloxacin (NOR). The results showed that the BiOBr-Bi (40 mmol/L NaBH4) had the highest activity. The degradation rate reached 97.2%. The half-life of NOR was shortened to 25 min. Moreover, the results of capture experiments indicated that the main active groups involved in the photocatalytic process under visible light conditions were ·O2- and h+. The reason why the activity of the BiOBr-Bi material photocatalyst increased is that the heterojunction formed by BiOBr with wider bandgap and Bi metal with a lower Fermi level effectively inhibits the recombination of holes and photogenerated electrons, which leads to the enhancement of oxidation capacity.

中文翻译：

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原位还原法在BiOBr表面制备具有增强光催化性能的BiOBr-Bi异质结复合材料

摘要 通过原位还原成功制备了一种具有改进光催化能力的新型BiOBr-Bi复合材料。X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、紫外-可见光谱 (UV-VisDRS)、X 射线光电子能谱 (XPS)、Brunner-Emmet-Teller 测量 (BET)、傅里叶变换红外光谱 ( FT-IR)、光致发光 (PL) 和电子顺磁共振 (EPR) 被用来表征光催化剂的形态结构、物理性质和表面元素组成。此外，通过降解抗生素诺氟沙星 (NOR) 来评估光催化活性。结果表明，BiOBr-Bi (40 mmol/L NaBH4) 的活性最高。降解率达到97.2%。NOR的半衰期缩短至25分钟。而且，捕获实验结果表明，在可见光条件下参与光催化过程的主要活性基团是·O2-和h+。BiOBr-Bi材料光催化剂活性提高的原因是带隙较宽的BiOBr与费米能级较低的Bi金属形成的异质结有效抑制了空穴和光生电子的复合，从而提高了氧化能力。