Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental & Resources Science , Zhejiang University , Hangzhou 310058 , P.R. China.
Zhejiang Provincial Engineering Research Center of Industrial Boiler & Furnace Flue Gas Pollution Control, Hangzhou 310027 , P.R. China.
Environ Sci Technol. 2018 Aug 7;52(15):8568-8577. doi: 10.1021/acs.est.8b00655. Epub 2018 Jul 18.
A "pseudo photocatalysis" process, being initiated between plasma and N-type semiconductors in the absence of light, was investigated for NO removal for the first time via dynamic probing of reaction processes by FT-IR spectra. It was demonstrated that N-type semiconductor catalysts could be activated to produce electron-hole (e-h) pairs by the collision of high-energy electrons (e*) from plasma. Due to the synergy of plasma and N-type semiconductors, major changes were noted in the conversion pathways and products. NO can be directly converted to NO and NO instead of toxic NO, owing to the formation of O and ·OH present in catalysts. New species like O or ·O may be generated from the interaction between catalyst-induced species and radicals in plasma at a higher SIE, leading to deep oxidation of existing NO to NO. Experiments with added trapping agents confirmed the contribution of e and h from catalysts. A series of possible reactions were proposed to describe reaction pathways and the mechanism of this synergistic effect. We established a novel system and realized an e*-activated "pseudo photocatalysis" behavior, facilitating the deep degradation of NO. We expect that this new strategy would provide a new idea for in-depth analysis of plasma-activated catalysis phenomenon.
首次通过傅里叶变换红外光谱（FT-IR）对反应过程进行动态探测，研究了在缺乏光照的情况下等离子体与 N 型半导体之间引发的“假光催化”过程在去除 NO 方面的应用。结果表明，等离子体中的高能电子（e*）与 N 型半导体催化剂的碰撞可以激活 N 型半导体催化剂，产生电子空穴（e-h）对。由于等离子体和 N 型半导体的协同作用，在转化途径和产物方面发生了重大变化。由于催化剂中存在 O 和·OH，NO 可以直接转化为 NO 和 NO，而不是有毒的 NO。在更高的 SIE 下，由于催化剂诱导的物质与等离子体中的自由基之间的相互作用，可能会产生 O 或·O 等新物质，导致现有 NO 的深度氧化为 NO。添加捕获剂的实验证实了催化剂中的 e 和 h 的贡献。提出了一系列可能的反应来描述反应途径和这种协同效应的机制。我们建立了一个新的系统，并实现了 e*-激活的“假光催化”行为，促进了 NO 的深度降解。我们期望这项新策略为深入分析等离子体激活催化现象提供新的思路。
