Zhou Xi, Zhang Jin, Wang Xuemei, Tan Tianqi, Fang Ruimei, Chen Si, Dong Fan
College of Environment and Resources, Chongqing Key Laboratory of Catalysis and New Environmental Materials, Chongqing Technology and Business University, Chongqing 400067, China.
Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313000, China.
J Hazard Mater. 2022 Aug 15;436:129271. doi: 10.1016/j.jhazmat.2022.129271. Epub 2022 Jun 3.
Photocatalysis technology prevails as a feasible option for air pollution control, in which high-efficiency charge separation and effective pollutant activation are the crucial issues. Here, this work designed Bi-metal@ BiO[BO(OH)] with oxygen vacancies (OVs) catalyst for photocatalytic oxidation of NO under visible light, to shed light on the above two processes. Experimental characterizations and density functional theory (DFT) calculations reveal that a unique electron transfer covalent loop（[BiO] → Bi-metal → O）can be formed during the reaction to guide the directional transfer of carriers, significantly improving the charge separation efficiency and the yield of active oxygen species. Simultaneously, the defect levels served by OVs also play a part. During the NO purification process, in-situ DRIFTS assisted with DFT calculations reveal that Bi metals could be functioned as electron donors to activate NO molecules and form NO, a key intermediate. This induces a new reaction path of NO → NO → NO to achieve the harmless conversion of NO, effectively restraining the generation of noxious intermediates (NO, NO). It is expected that this study would inspire the design of more artful photocatalysts for effective charge transfer and safe pollutants purification.
光催化技术作为一种可行的空气污染控制方案而盛行，其中高效的电荷分离和有效的污染物活化是关键问题。在此，本工作设计了具有氧空位（OVs）的双金属@BiO[BO(OH)]催化剂用于可见光下NO的光催化氧化，以阐明上述两个过程。实验表征和密度泛函理论（DFT）计算表明，反应过程中可形成独特的电子转移共价环（[BiO]→双金属→O）来引导载流子的定向转移，显著提高电荷分离效率和活性氧物种的产率。同时，由氧空位提供的缺陷能级也发挥作用。在NO净化过程中，原位漫反射红外傅里叶变换光谱（DRIFTS）结合DFT计算表明，双金属可作为电子供体活化NO分子并形成关键中间体NO。这引发了一条新的NO→NO→NO反应路径以实现NO的无害化转化，有效抑制有害中间体（NO、NO）的生成。预计本研究将激发设计更巧妙的光催化剂以实现有效的电荷转移和安全的污染物净化。
