张安超, 张旭, 张倩倩,等.三维球状BiOI/BiOBr异质结光催化剂制备及其光催化脱汞性能[J].河南理工大学学报（自然科学版）,2024,43(1):78-87.

ZHANG A C, ZHANG X, ZHANG Q Q, et al.Preparation of three-dimensional spherical BiOI/BiOBr heterojunction photocatalyst and its photocatalytic mercury removal performance[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(1):78-87.

三维球状BiOI/BiOBr异质结光催化剂制备及其光催化脱汞性能

张安超, 张旭, 张倩倩, 李海霞, 王华, 梅艳阳, 郑海坤, 陈国艳

河南理工大学 机械与动力工程学院，河南 焦作 454000

摘要:光催化氧化技术是治理污染物排放的重要手段。目的 为增强BiOBr对可见光的利用率并提高其光催化活性，方法 采用共沉淀法制备碘掺杂的三维球状BiOI/BiOBr异质结光催化剂，使用X射线衍射、紫外-可见漫反射光谱、扫描电子显微镜扫描、N₂吸附-脱附、X射线光电子能谱和电子自旋共振波谱等对样品结构进行表征，开展光催化脱除单质汞（Hg⁰）性能研究。结果 结果表明，随着I含量升高，BiOBr衍射峰逐渐降低，BiOI衍射峰逐渐增强；BiOI/BiOBr复合光催化剂保留了BiOBr的三维微球形貌，BiOI均匀分散于BiOBr表面，且复合后比表面积有所提高，较大的表面积能提供更多的反应空间，促进活性自由基产生和提高光催化剂性能；与BiOBr相比，复合光催化剂的带隙能降低，可见光响应能力大幅增强。BiOI/BiOBr光催化脱汞性能高于单纯BiOI与单纯BiOBr；BiOI和BiOBr摩尔比为2∶8时，光催化剂脱汞效率高达98%，是单纯BiOBr的2.58倍；酸性条件下制备的BiOI/BiOBr异质结光催化剂会与碱性溶液反应，引起光催化剂成分的变化，进而影响光催化剂的催化性能；Hg⁰高效光催化氧化过程中，阴离子超氧自由基（ˑ）和空穴（h⁺）是主要活性物质。结论 研究结果可为卤氧化铋光催化剂的复合制备及其在脱汞领域的应用提供理论依据。

关键词:异质结;光催化剂;溴氧化铋;碘氧化铋;单质汞

doi:doi：10.16186/j.cnki.1673-9787.2021100024

基金项目:国家自然科学基金资助项目（51676064）；河南省高校科技创新人才资助项目（19HASTIT045）；河南理工大学创新型科研团队研究项目（T2020-3）

收稿日期:2021/10/12

修回日期:2022/03/15

出版日期:2024/01/25

Preparation of three-dimensional spherical BiOI/BiOBr heterojunction photocatalyst and its photocatalytic mercury removal performance

ZHANG Anchao, ZHANG Xu, ZHANG Qianqian, LI Haixia, WANG Hua, MEI Yanyang, ZHENG Haikun, CHEN Guoyan

School of Mechanical and Power Engineering，Henan Polytechnic University，Jiaozuo 454000，Henan，China

Abstract:Photocatalytic oxidation technology is an important strategy to control pollutant emission. Objective To enhance the utilization ratio of visible light and improve its photocatalytic activity of BiOBr， Methods the iodine doped three-dimensional spherical BiOI/BiOBr heterojunction photocatalysts were prepared by simple co-precipitation method.The structures of the samples were characterized by X-ray diffraction，UV-visible diffuse reflectance spectroscopy，scanning electron microscopy，N₂ adsorption-desorption，X-ray photoelectron spectroscopy and electron spin resonance spectroscopy，and the performance of photocatalytic removal of elemental mercury（Hg⁰） was studied. Results The results showed that with the increase of iodine content，the diffraction peak intensity of BiOBr decreased，while the diffraction peak intensity of BiOI gradually increased.The BiOI/BiOBr composite photocatalyst retained the three-dimensional microsphere morphology of BiOBr，and BiOI was uniformly dispersed on the surface of BiOBr，meanwhile some new specific surface areas were generated，which can provide more reaction space and promote the generation of active free radicals and improve the performance of the photocatalyst.Compared with BiOBr，the band gap energy of the composite photocatalyst was greatly reduced，and the visible light response ability was significantly enhanced.The photocatalytic Hg⁰ removal performances of BiOI/BiOBr photocatalysts were higher than those of BiOI and BiOBr.When the molar ratio of BiOI to BiOBr was 2∶8，the Hg⁰ removal efficiency of the photocatalyst was up to 98%，which was 2.58 times that of BiOBr.The BiOI/BiOBr heterojunction photocatalyst prepared under acidic conditions would react with alkaline solution，which could cause the changes of the composition of the photocatalyst，and then affect the catalytic performance of the photocatalyst.The radicals capture experiment showed that anionic superoxide radicals（ˑ）and holes（h⁺） were important active substances in the process of Hg⁰ photocatalytic removal. Conclusion The research has laid a theoretical foundation for the composite preparation of bismuth halide oxide photocatalyst and its application in the field of mercury removal.

Key words:heterojunction;photocatalyst;BiOBr;BiOI;elemental mercury