Chongqing Key Laboratory of Catalysis and New Environmental Materials, College of Environment and Resources, Chongqing Technology and Business University , Chongqing 400067, China.
College of Architecture and Environment, Institute of New Energy and Low Carbon Technology, Sichuan University , Sichuan 610065, China.
Environ Sci Technol. 2017 Sep 19;51(18):10682-10690. doi: 10.1021/acs.est.7b00974. Epub 2017 Aug 30.
This work demonstrates the first molecular-level conversion pathway of NO oxidation over a novel SrO-clusters@amorphous carbon nitride (SCO-ACN) photocatalyst, which is synthesized via copyrolysis of urea and SrCO. The inclusion of SrCO is crucial in the formation of the amorphous carbon nitride (ACN) and SrO clusters by attacking the intralayer hydrogen bonds at the edge sites of graphitic carbon nitride (CN). The amorphous nature of ACN can promote the transportation, migration, and transformation of charge carriers on SCO-ACN. And the SrO clusters are identified as the newly formed active centers to facilitate the activation of NO via the formation of Sr-NO, which essentially promotes the conversion of NO to the final products. The combined effects of the amorphous structure and SrO clusters impart outstanding photocatalytic NO removal efficiency to the SCO-ACN under visible-light irradiation. To reveal the photocatalytic mechanism, the adsorption and photocatalytic oxidation of NO over CN and SCO-ACN are analyzed by in situ DRIFTS, and the intermediates and conversion pathways are elucidated and compared. This work presents a novel in situ DRIFTS-based strategy to explore the photocatalytic reaction pathway of NO oxidation, which is quite beneficial to understand the mechanism underlying the photocatalytic reaction and advance the development of photocatalytic technology for environmental remediation.
这项工作展示了在一种新型 SrO-团簇@无定形碳氮化物（SCO-ACN）光催化剂上，NO 氧化的第一个分子水平转化途径，该催化剂是通过尿素和 SrCO 的共热解合成的。SrCO 的掺入对于通过攻击石墨碳氮化物（CN）层间边缘位点上的氢键来形成无定形碳氮化物（ACN）和 SrO 团簇是至关重要的。ACN 的无定形性质可以促进 SCO-ACN 上载流子的输运、迁移和转化。并且 SrO 团簇被鉴定为新形成的活性中心，通过形成 Sr-NO 来促进 NO 的活化，这实质上促进了 NO 向最终产物的转化。无定形结构和 SrO 团簇的综合作用赋予了 SCO-ACN 在可见光照射下出色的光催化 NO 去除效率。为了揭示光催化机制，通过原位 DRIFTS 分析了 CN 和 SCO-ACN 对 NO 的吸附和光催化氧化，阐明并比较了中间产物和转化途径。这项工作提出了一种新的基于原位 DRIFTS 的策略来探索 NO 氧化的光催化反应途径，这对于理解光催化反应的机制和推进用于环境修复的光催化技术的发展非常有益。
