Aqueous phase photolysis of 4-nitrocatechol: Reaction kinetics, evolutions of chemical composition, light absorption and oxidation potential

被引：0

作者：

Lei, Ruoyuan ^{[1
]}

Sha, Yingying ^{[1
]}

Meng, Haifeng ^{[1
]}

Huang, Yu ^{[1
]}

Ye, Jianhuai ^{[2
]}

Huang, Dan Dan ^{[3
]}

Zhang, Yunjiang ^{[1
]}

Wu, Yun ^{[1
]}

Li, Yongjie ^{[4
]}

Ge, Xinlei ^{[1
,5
]}

机构：

[1] Nanjing Univ Informat Sci & Technol, Collaborat Innovat Ctr Atmospher Environm & Equipm, Sch Environm Sci & Engn, Jiangsu Key Lab Atmospher Environm Monitoring & Po, Nanjing 210044, Peoples R China

[2] Southern Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen Key Lab Precis Measurement & Early Warnin, Shenzhen 518055, Peoples R China

[3] Shanghai Acad Environm Sci, State Environm Protect Key Lab Format & Prevent Ur, Shanghai 200233, Peoples R China

[4] Univ Macau, Fac Sci & Technol, Ctr Reg Oceans, Dept Civil & Environm Engn, Taipa 999078, Peoples R China

[5] Anhui Jianzhu Univ, Sch Environm & Energy Engn, Hefei 230601, Peoples R China

来源：

ATMOSPHERIC ENVIRONMENT | 2025年 / 343卷

关键词：

4-Nitrocatechol; Organic triplet state; Light absorption brown carbon; Oxidation potential; SECONDARY ORGANIC AEROSOL; PARTICULATE NITRATED PHENOLS; BROWN CARBON; PHOTOCHEMICAL OXIDATION; HYDROXYL RADICALS; CHEMISTRY; PHOTOOXIDATION; ENVIRONMENTS; NITROPHENOLS; COMBUSTION;

D O I：

10.1016/j.atmosenv.2024.120981

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

4-nitrocatechol (4NC) is a model compound of nitrophenols, an important group pf light-absorbing species, a.k.a., brown carbon (BrC), that have significant impacts on air quality and radiation forcing. This work aims to elucidate the kinetics, chemical and optical properties as well as oxidation potential (OP) of 4NC during aqueous photolysis. Results show that hydroxyl radical (center dot OH) initiated photo-oxidation has the fastest reaction rate (6.1 x 10(-5) s(-1)) followed by organic triplet state (C-3 & lowast;) induced photolysis (3.8 x 10(-5) s(-1)) and direct photolysis (2.4 x 10(-5) s(-1)); the second-order rate constant of center dot OH with 4NC is determined to be 4.3 x 10(10) M(-1)s(-1). Reaction pathways of C-3 & lowast;-initiated photolysis and center dot OH-initiated photolysis are largely different, with the former generating more oxygenated species, but their mass yields of products after 12 h of irradiation are close (similar to 40 %). Aqueous ageing of 4NC overall leads to the decrease of light absorption, and the photo-bleaching rates are in an order of center dot OH (2.58 x 10(-5) s(-1)) > C-3 & lowast; (1.06 x 10(-5) s(-1)) > direct photolysis (5.83 x 10(-6) s(-1)); the second-order photo-bleaching rate constant of center dot OH with 4NC is 1.77 x 10(10) M(-1)s(-1). On the other hand, aqueous ageing can also produce BrC species (not sufficient to offset the photo-bleaching effect) of which some nitrogen-containing organics are an important part, and C-3 & lowast;-photolysis has the strongest production ability. Furthermore, aqueous photolysis of 4NC can decrease its OP, especially the center dot OH-photolysis products are nearly non-toxic while those from C-3 & lowast;-photolysis still has significantly high OP at the end of oxidation. Finally, we estimated the atmospheric lifetimes of 4NC against center dot OH in different atmospheric environments, which range from a few seconds to tens of hours.

引用

页数：10