通过在水相中的大气细菌衍生的有机物质有效地产生反应性氧化剂
Yushuo Liu1,2, Yitao Li1,2, Wing Lam Chan1
1School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China.
Environmental science & technology
|March 28, 2025
概括
生物气溶,如细胞有机物和细胞外聚合物质,在大气中有效地产生反应性中间体 (氧化剂). 它们的光化学行为受到分子性质的影响,影响大气化学.
科学领域:
- 大气中的化学成分
- 摄影化学的使用.
- 环境科学环境科学
背景情况:
- 像基基 (•OH),单点氧 (1O2*) 和有机三重激发状态 (3C*) 这样的反应性中间体 (RIs) 是大气气溶形成和转化中的关键氧化剂.
- 生物气溶在大气中很常见,但它们的光化学作用和对大气光化学的贡献仍然不明.
研究的目的:
- 研究来自大气细菌的水相细胞有机物 (COM) 和细胞外聚合物质 (EPS) 的光化学行为.
- 通过COM和EPS确定3C*,1O2*和OH的光化学生产.
- 探索分子大小,芳香度和MW对RI生产的影响.
主要方法:
- 从大气PM2.5中分离出来的培养细菌被用来获得COM和EPS.
- 测量了3C*,1O2*和OH的光化学生产.
- 确定了表面量子产量 (ΦRI) 和稳定状态度 ([RI]ss).
- 机器学习模型被用来根据光学和化学特性预测氧化剂的产生.
主要成果:
- 对于1O2*和3C*的生产,COM和EPS含有高效的光敏剂,其 ΦRI 分别高达10%和5%.
- 较高分子量 (MW) 分数显示FRI和[RI]ss下降,归因于破坏光化学过程的电荷转移相互作用.
- 染色体/光体的分子大小和芳香度与MW相关.
结论:
- 大气中的生物气溶 (COM和EPS) 是反应性中间体的重要来源,有助于大气光化学.
- 分子特性,特别是MW和相关的电荷转移相互作用,调节氧化剂生产的效率.
- 这项研究为生物气溶光化学对大气的影响提供了关键的见解.
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