一种用于水降解光催化过程的高效双氧化二碘微球合成方法
Summary
本文介绍了一种合成方法, 以获得在 Uv-a-可见光照射下, 在水中对环丙沙星等有机污染物进行光催化去除的高效微球。
Abstract
氧钡是一种很有前途的太阳-环境光催化材料。鉴于这类材料的物理结构与其光催化性能密切相关, 有必要对合成方法进行标准化, 以获得功能最强的结构, 从而获得最高的光催化性能效率。在这里, 我们报告了一个可靠的途径, 以获得 bioi 微球通过溶热过程, 使用 Bi (NO3)3和碘化钾 (ki) 作为前体和乙二醇作为模板。该合成在一个150毫升的高压灭菌器中标准化, 在126°c 的18小时内进行。这就产生了2-3 微米大小的介孔微球, 具有相关的比表面积 (61.3 米2/)。缩短合成过程中的反应时间会产生非晶态结构, 而较高的温度会导致微球的孔隙率略有增加, 对光催化性能没有影响。这些材料在 Uv-a/可见光照射下具有光活性, 可使抗生素环丙沙星在水中降解。这种方法已被证明是有效的实验室间测试, 获得类似的 BiOI 微球在墨西哥和智利的研究小组。
Introduction
迄今为止, 已经合成了大量半导体, 其目的是在可见光照射下实现高活性的光催化剂, 以降解有机化合物或以氢1,2的形式产生可再生能源。氧氧化物 (x = cl、br 或 i) 是这种应用的候选产品, 因为它们在可见光或模拟阳光照射下具有较高的光催化效率, 为 3,4。氧卤化物的带隙能 (e g)随卤化物原子序数的增加而减小;因此, BiOI 是显示最低活化能 (Eg = 1.8 ev)5的材料。通过范德华力与钡原子结合的碘化物原子, 产生了一个有利于电荷载体向半导体表面迁移的电场, 从而触发光催化过程4,6。此外, 晶粒的结构在电荷载体的分离中具有关键的作用。(001) 平面和三维结构 (如微球) 中的高取向结构可促进辐照时的电荷载体分离, 从而提高光催化性能7,8,9,10,11,12. 鉴于此, 有必要开发可靠的合成方法, 以获得提高氧卤化钡材料光活性的结构。
到目前为止, 溶热法是获得 bioi 微球 13、14、15、16的最常用和研究的途径。还报告了使用离子液体的一些方法 17, 尽管与这些方法有关的费用可能更高。微球结构通常是使用有机溶剂, 如乙二醇, 作为协调剂形成金属烷氧基, 导致 [Bi 2o2]2 +种类逐渐自组装 18,19. 与乙二醇一起使用溶热路线, 通过改变反应中的温度和反应时间4、18等关键参数, 促进了不同形态的形成。关于获得 BiOI 微球的合成方法, 有大量的文献, 这些文献显示了实现高光活性结构的对比信息。该详细协议旨在展示一种可靠的合成方法, 以获得生物交换微球在水中污染物光催化降解方面的高功能。我们打算帮助新的研究人员成功地获得这种材料, 避免与合成过程有关的最常见的陷阱。
Protocol
注: 在使用化学试剂之前, 请阅读所有材料安全数据表 (MSDS)。穿着实验室外套和手套, 遵守所有的安全规程。在光催化测试中佩戴紫外线防护安全眼镜。请注意, 与前体相比, 纳米材料可能会产生重要的危险影响。 1. BiOI 微球的制备 对于溶液 1, 在玻璃烧杯中的60毫升乙二醇中溶解2.9104 克的硝酸钡 (BI(No3)3;对于溶液 2, 将 0….
Representative Results
采用该合成方法成功合成了 BiOI 的三维微结构。图 1a-c所示的 sem 图像证实了这一点。微球是由 [Bi2o2]2 + 的层流结构形成的, 由两个碘化原子1结合。微球的形成取决于太阳热过程的温度和时间, 因为这些参数决定了氧卤化物3、4、<su…
Discussion
我们认为前体的混合物是 BiOI 微球溶热合成的关键步骤。KI 溶液缓慢滴入 Bi (NO3) 3 溶液 (最大为 1 mlmin)对于获得介孔微球至关重要, 因为它允许 [bi2o2]+ 2 板的缓慢形成和自组装, 然后与碘化物原子结合形成 BiOI 层压板。层板是溶热步骤中微球的砖 (图 1)。温度和反应时间是太阳热合成的关键因素, 因为高温最初允许 [bi2o2]+</su…
Offenlegungen
The authors have nothing to disclose.
Acknowledgements
提交人感谢墨西哥城市技术秘书通过资助的主管西/2016年主管项目和国家科学和技术发展基金为开展这项工作提供的资源。智利 (FONDECYT 11170431)。
Materials
| Bismuth(III) nitrate pentahydrate | Sigma Aldrich | 383074 | ACS reagent, ≥98.0% |
| Potassium iodide | Sigma Aldrich | 746428 | ACS reagent, ≥98.0% |
| Ethylene glycol | Sigma Aldrich | 324558 | Anhydrous, 99.8% |
| Ethanol | Meyer | 5405 | Technical Grade, 96% |
| Ciprofloxacin | Sigma Aldrich | 17850 | HPLC, ≥98.0% |
| Cary 5000 UV-Vis-NIR spectrophotometer | Agilent | Used for the Band gap determination by the Tauc model. | |
| JSM-5600 Scanning Electron Microscope | JOEL | Used for the SEM images. | |
| Autosob-1 | Qantachrome Instruments | Used for the determination of surface area and pore diameter. | |
| TOC-L Total Organic Carbon Analyzer | Shimadzu | Used for determination of total organic carbon in water samples. | |
| Bruker AXS D8 Advance – X-ray Diffraction | Bruker | Determination of crystal structure and crystallite size |
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Diesen Artikel zitieren
Durán-Álvarez, J. C., Martínez, C., Mera, A. C., Del Angel, R., Gutiérrez-Moreno, N. J., Zanella, R. A Facile Synthetic Method to Obtain Bismuth Oxyiodide Microspheres Highly Functional for the Photocatalytic Processes of Water Depuration. J. Vis. Exp. (145), e59006, doi:10.3791/59006 (2019).