2021721Environmental Science & Technology在线发表朱彤教授课题组题为“Using Micro-Raman Spectroscopy to Investigate Chemical Composition, Mixing States, and Heterogeneous Reactions of Individual Atmospheric Particles的论文,报道了成功使用显微拉曼光谱研究实际大气单颗粒化学组成、混合态及非均相化学反应的结果。

测量大气单颗粒的化学组成可以为研究颗粒物在大气中的混合状态和非均相反应提供直接证据。以往常用电镜-能谱(TEM/SEM-EDX)和单颗粒气溶胶质谱(SPAMS)来测量大气单颗粒的化学组成。这两种方法都需要在高真空下测量,大气颗粒中的挥发组分可能会部分或者完全损失。并且这两种方法只能分别测量元素组成(EDX)和离子碎片(SPAMS)。而显微拉曼光谱可以在常温常压下直接测量大气单颗粒中的分子和官能团朱彤课题组国内外少数几个课题组已用显微拉曼光谱研究模拟大气单颗粒的非均相反应然而尚不清楚显微拉曼光谱能否用于实际大气单颗粒化学组成、混合态及非均相反应的研究。

针对采集11北京大气单颗粒样品,朱彤课题组使用显微拉曼光谱测量了样品中1200个单颗粒的化学组成。根据特征拉曼光谱,在单颗粒中鉴定出了(NH4)2SO4NH4NO3黑碳有机物NaNO3和多种矿质组研究发现(NH4)2SO4NH4NO3在单颗粒中既可以单独存在,也可以内混合的形式存在。23%的含黑碳单颗粒和57%的含有机物单颗粒中也含有无机物NH4NO3(NH4)2SO4矿质组分和NaNO3,表明含碳组分和无机物在大气单颗粒中常以内混合形式存在。鉴定出的矿质组分包括CaCO3CaMg(CO3)2SiO2,以及矿质组分在大气中非均相反应产物Ca(NO3)2Mg(NO3)2CaSO4根据矿质组分的混合状态,推测CaCO3在大气中可能的非均相反应途径:CaCO3与含氮和含硫酸性气体反应生成Ca(NO3)2CaSO4。该研究表明显微拉曼光谱是研究大气单颗粒化学组成混合态非均相反应的有力工具。

4166am手机app博士后王明金和已出站博士后郑楠为该论文的共同第一作者,朱彤为通讯作者。该研究得到了国家自然科学基金 (91844000 4142106420637020)国家科技部(2008AA062503)国家博士后基金(20100470166)111计划城市空气污染和健康效应(B20009)的支持。

论文链接:

Wang MJ#, Zheng N#, Zhao DF, Shang J, and Zhu T*, Using Micro-Raman Spectroscopy to Investigate Chemical Composition, Mixing States, and Heterogeneous Reactions of Individual Atmospheric Particles, Environmental Science & Technology, 2021, https://doi.org/10.1021/acs.est.1c01242

相关论文链接:

  1. Yu T#, Zhao DF#, Song XJ, Zhu T*, NO2-initiated multiphase oxidation of SO2 by O2 on CaCO3 particles, Atmospheric Chemistry and Physics, 18(9), 2018, 6679–6689, https://doi.org/10.5194/acp-18-6679-2018
  2. Zhao DF#, Song XJ#, Zhu T*, Zhang ZF, Liu YJ, Shang J, Multiphase oxidation of SO2 by NO2 on CaCO3 particles, Atmospheric Chemistry and Physics, 18(4), 2018, 2481–2493, https://doi.org/10.5194/acp-18-2481-2018
  3. Wang MJ#, Zheng N#, Zhu T*, Shang J, Yu T, Song XJ, Zhao DF, Guan Y, Tian YC, Using X-ray computed tomography and micro-Raman spectrometry to measure individual particle surface area, volume, and morphology towards investigating atmospheric heterogeneous reactions, Journal of Environmental Sciences, 69, 2018, 23–32, https://doi.org/10.1016/j.jes.2018.03.015
  4. Liu YJ, Zhu T*, Zhao DF, Zhang ZF, Investigation of the hygroscopic properties of Ca(NO3)2 and internally mixed Ca(NO3)2/CaCO3 particles by micro-Raman spectrometry, Atmospheric Chemistry and Physics, 8(23), 2008, 7205–7215, https://doi.org/10.5194/acp-8-7205-2008
  5. Zhao DF, Zhu T*, Chen Q, Liu YJ, Zhang ZF, Raman micro-spectrometry as a technique for investigating heterogeneous reactions on individual atmospheric particles, Science China: Chemistry, 54(1), 2011, 154–160, https://doi.org/10.1007/s11426-010-4182-x
  
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