Yang Jian, Wang Qiangke, Luo Xuefeng, Han Chuang, Liang Yujun, Yang Gui, Zhang Xiaorui, Zeng Zikang, Wang Guangzhao
Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, School of Electronic Information Engineering, Yangtze Normal University, Chongqing 408100, China.
J Colloid Interface Sci. 2023 Dec;651:805-817. doi: 10.1016/j.jcis.2023.08.048. Epub 2023 Aug 8.
Heterojunctions have been proved to be the promising photocatalysts for hazardous contaminants removal, but the inferior interfacial contact, low carrier mobility and random carrier diffusion seriously hamper the photoactivity improvement of the conventional heterojunctions. Herein, SO chemically bonded p-n oriented heterostructure is fabricated via selectively anchoring of p-type AgS nanoparticles on the lateral facet of n-type BiTaOCl nanosheet. Such a p-n heterojunction engineering on specific facet of BiTaOCl semiconductor derives ingenious double internal electric field (IEF), which not only effectively creates the spatially separated oxidation and reduction sites, but also delivers the powerful driving forces for impactful spatial directed photocarrier transfer along the cascade path. Additionally, our experimental and theoretical analyses jointly signify that the interfacial SO bond could serve as an efficient atomic-level interfacial channel, which is conducive to encouraging the vectorial charge separation and migration kinetic. As a result, the AgS/BiTaOCl oriented heterojunction exhibits significantly enhanced visible light driven photocatalytic redox ability for tetracycline oxidation and hexavalent chromium reduction than those of single component and the traditional random/mixed heterojunctions. This study could provide a deeper insight into the synergistic effects of multi-IEF modulation and interfacial chemical bond bridging on optimizing the photogenerated carrier behaviors.
异质结已被证明是用于去除有害污染物的有前景的光催化剂，但较差的界面接触、低载流子迁移率和随机的载流子扩散严重阻碍了传统异质结光活性的提高。在此，通过将p型AgS纳米颗粒选择性地锚定在n型BiTaOCl纳米片的侧面，制备了SO化学键合的p-n取向异质结构。在BiTaOCl半导体特定晶面上进行的这种p-n异质结工程产生了巧妙的双内电场（IEF），这不仅有效地创建了空间分离的氧化和还原位点，还为沿级联路径的有影响力的空间定向光载流子转移提供了强大的驱动力。此外，我们的实验和理论分析共同表明，界面SO键可以作为一个有效的原子级界面通道，有利于促进矢量电荷分离和迁移动力学。结果，与单一组分和传统的随机/混合异质结相比，AgS/BiTaOCl取向异质结在可见光驱动下对四环素氧化和六价铬还原表现出显著增强的光催化氧化还原能力。这项研究可以更深入地了解多IEF调制和界面化学键桥接在优化光生载流子行为方面的协同效应。
