Plasma-treatment of polymeric carbon nitride for efficient NO abatement under visible light
Plasma-treatment of polymeric carbon nitride for efficient NO abatement under visible light
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DOI：
10.1088/1361-6463/ac782d
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发表时间：
2022-06
期刊：
影响因子：
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通讯作者：
Qimiao Zeng;J. Ni;D. Mariotti;Lanying Lu;Hong Chen;C. Ni
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作者：
Qimiao Zeng;J. Ni;D. Mariotti;Lanying Lu;Hong Chen;C. Ni
氮氧化物（NOx）是影响人类健康的大气污染物之一，光催化技术被认为是一种有效的治理方法。聚合氮化碳（PCN）是一种低成本的二维高分子光催化剂，对可见光敏感，但其光催化效率有待提高。在这项研究中，PCN处理使用一个简易的环境压力介质阻挡放电（DBD）等离子体在空气中，Ar和Ar-5%H2流。光谱表征和NO去除实验表明，DBD等离子体不仅没有破坏PCN的晶体结构，而且提高了光生电荷的分离效率，增强了NO的去除能力。在可见光照射下，Ar-5%H2等离子体处理的最佳去除效率为69.19%，对硝酸盐的选择性为90.51%。氢等离子体对PCN表面进行刻蚀，导致PCN表面产生更多的缺陷（碳空位）和羰基，而空气等离子体则增加了PCN表面的悬浮-NOx键合，从而增加了光照下的NOx排放。在放电过程中产生的高能电子和活性自由基可以引起PCN的表面改性，以实现有效的包覆。
Photocatalysis is considered to be efficient in combatting emission nitrogen oxide (NO x ), which is one of the atmospheric pollutants affecting human health. Polymeric carbon nitride (PCN) is a low-cost polymeric photocatalyst with a two-dimensional structure that is sensitive to the visible sunlight in the solar spectrum, but its photocatalytic efficiency needs to be enhanced for the purpose of pollutant abatement. In this study, PCN was treated using a facile ambient pressure dielectric barrier discharge (DBD) plasma in air, Ar and Ar-5% H2 flow. According to the spectroscopic characterization and NO removal tests, the DBD plasma did not destroy the crystal structure of PCN, but improved the separation efficiency of photogenerated charges and enhanced the capacity of NO abatement. The plasma treatment in Ar-5% H2 showed an optimal removal efficiency of 69.19% and a selectivity for nitrate of 90.51% under visible light irradiation. The hydrogen plasma etched the PCN surface, resulting in more defects (carbon vacancies) and carbonyl group on the surface, while the air plasma was found to increase the suspending –NO x bonding on the surface for the increased NO x emission under illumination. The generation of high-energy electron and reactive radicals in the electrical discharges could cause the surface modification of PCN for efficient photocatalysis.