| BiOBr/g-C3N4 S型异质结无H2O2光-自芬顿高效催化降解RhB |
| Efficient degradation of RhB over BiOBr/g-C3N4 S-scheme heterojunction by a H2O2-free photo-self-Fenton catalysis |
| 作者 | 单位 | E-mail | | 章辉 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 程丽青 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 胡明玥 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 李明宇 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 郑健飞 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 辛思甜 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 方彩红 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 陈恒 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 杨毅琼 | 湖北工业大学材料与化学工程学院, 武汉 430068 | | | 聂龙辉 | 湖北工业大学材料与化学工程学院, 武汉 430068
新材料与绿色制造引智创新示范基地, 武汉 430068 | nielonghui@mail.hbut.edu.cn |
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| 摘要: 通过焙烧-超声混合法成功地制备了BiOBr/g-C3N4 S型异质结复合光催化剂。采用多种表征手段对样品物理属性进行了表征，包括X射线多晶粉末衍射仪（XRD）、扫描电子显微镜（SEM）、X射线光电子能谱（XPS）、紫外可见漫反射光谱（UV-VisDRS）。研究了所制备样品有/无Fe3+的光-自芬顿催化/光催化降解罗丹明B （RhB）性能。通过捕获实验确定了光催化反应中的主要活性物种，提出了光-自芬顿反应的降解机理。研究结果表明，BiOBr/g-C3N4 S型异质结能原位生成H2O2，添加Fe3+后，H2O2被原位活化成活性物种且光生电流和载流子分离效率获得显著提高。该光-自芬顿过程能高效降解RhB，其反应速率常数为0.208 min-1，约为无Fe3+光催化反应速率常数的5.3倍，在光-自芬顿循环使用过程中表现出良好的稳定性。Fe3+的加入促进了光生电荷的分离和H2O2的活化，超氧阴离子自由基（·O2-）、空穴和羟基是光-自芬顿催化过程中的主要活性物种，且·O2-作用更大。 |
| 关键词: BiOBr/g-C3N4 S型异质结 光-自芬顿反应 多相催化 催化机理 |
| 基金项目: 国家自然科学基金（No.51572074）、毒品分析及禁毒技术公安部重点实验室开放课题（No.YNPL-B2021002）和大学生创新创业项目（No.202210500063）资助。 |
| Abstract: The fabrication of the BiOBr/g-C3N4 S-scheme heterojunction is an effective way to improve photocatalytic activity. Yet, its photocatalytic activity is expected to further improve, and its photo-Fenton catalytic activity for pollutant degradation in the absence of H2O2 has not been investigated up to now. In this work, a BiOBr/g-C3N4 S-scheme heterojunction photocatalyst was successfully prepared by a calcination-ultrasonic mixing method. Herein, its photo-self-Fenton catalytic activity was investigated for the first time in the absence of H2O2. The physical properties of the samples were characterized by X-ray polycrystalline powder diffractometer (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Photocatalytic and photo-self-Fenton catalytic degradation of rhodamine B (RhB) were studied over BiOBr/g-C3N4 S-scheme heterojunction without/with Fe3+ in the absence of H2O2, respectively. The main active species in the photo-self-Fenton catalytic reaction were determined by capturing experiments, and the degradation mechanism of the photo-self-Fenton catalysis was proposed. The results showed that H2O2 could be formed in situ over the BiOBr/g-C3N4 S-scheme heterojunction under visible-light irradiation. The photogenerated current and the separation efficiency of photo-generated carriers can be greatly improved in the presence of Fe3+ over BiOBr/g-C3N4 S-scheme heterojunction, resulting in the enhancement of photocatalytic efficiency for RhB degradation in the photo-self-Fenton process than in the photocatalytic reaction without Fe3+. The reaction rate constant of photo-self-Fenton over BiOBr/g-C3N4 S-scheme heterojunction with Fe3+ was 0.208 min-1, which was about 5.3 times that of photocatalysis without Fe3+. It also showed good stability in the recycling experiment. The addition of Fe3+ promotes the separation of photogenerated charges and the activation of generated H2O2 by the Fe2+/Fe3+ redox cycle. The results of capturing experiments show that superoxide anion radicals (·O2-) and holes (h+) are found the main active species, and ·O2-plays a more important role in photo-self-Fenton catalysis. |
| Keywords: BiOBr/g-C3N4 S-scheme heterojunction photo-self-Fenton reaction heterogenerous catalysis catalytic mechanism |
| 投稿时间：2023-03-26 修订日期：2023-10-09 |
| 摘要点击次数: 1926 |
| 全文下载次数: 1207 |
| 章辉,程丽青,胡明玥,李明宇,郑健飞,辛思甜,方彩红,陈恒,杨毅琼,聂龙辉.BiOBr/g-C3N4 S型异质结无H2O2光-自芬顿高效催化降解RhB[J].无机化学学报,2023,39(11):2121-2130. |
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