Complexities of Photosensitization in Atmospheric Particles DOI Creative Commons
Zhancong Liang, Yongjie Li,

Brix Raphael Go

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(11), P. 1333 - 1351

Published: Oct. 10, 2024

Brown carbons (BrCs) play a pivotal role in the light absorption by aerosol particulates exerting positive radiative forcing effect that contributes to global warming. Beyond impacts on balance, some BrCs, as photosensitizers, can generate reactive triplet-state molecules toward various atmospheric upon photoexcitation. The significance of photosensitization has been increasingly recognized, particularly context escalated wildfire incidents emit substantial BrCs. We focus complex discussing current challenges, including (1) diverse reactivities photosensitizer mixture particles, (2) methodologies for investigating processes, (3) driving factors photosensitization, and (4) typical pathways mechanisms photosensitized reactions. Lastly, we advise future research refined parametrization triplet singlet oxygen concentrations, alongside their reactivities.

Language: Английский

Tropospheric Multiphase Chemistry: Excited Triplet States Compete with OH Radicals and Singlet Molecular Oxygen DOI

Emma A. Petersen-Sonn,

Marcello Brigante, Laurent Deguillaume

et al.

ACS Earth and Space Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 12, 2025

Excited triplet states of organic molecules (3C*) present in aerosols have been investigated for their ability as oxidants the aqueous phase. Aerosols were collected Grenoble (France), winter and summer times during period December 2021 through June 2022, steady-state concentrations quantum yields 3C*, 1O2, •OH determined under solar-simulated conditions using various specific chemical probes. For comparison purposes, these three at sample 10 mg C L–1. The resulting all larger samples than ones ranked follows [1O2]ss > [3C*]ss [OH]ss agreement with previous reports. However, those do exhibit different reactivities classes compounds, which can be a generic way kOH,ORG k3C*,ORG k1O2,ORG. If we combine reactivity oxidants, it appears that matter are main most compounds. This study emphasizes relevance excited compared to singlet oxygen OH radicals need additional studies conditions.

Language: Английский

Citations

1
Efficient Production of Reactive Oxidants by Atmospheric Bacterial-Derived Organic Matter in the Aqueous Phase DOI
Yushuo Liu, Yitao Li, Wing Lam Chan

et al.

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: March 27, 2025

Hydroxyl radicals (•OH), singlet oxygen (1O2*), and organic triplet excited states (3C*) play key roles as oxidants ("reactive intermediates (RIs)") in forming oxidizing aqueous aerosols. Bioaerosols are ubiquitous the atmosphere, but little is known about their photochemical behavior contributions to atmospheric photochemistry. We investigated of aqueous-phase cellular matter (COM) extracellular polymeric substances (EPS) from cultured bacteria isolated PM2.5, focusing on production 3C*, 1O2*, •OH. The molecular size aromaticity chromophores fluorophores COM EPS increased with weight (MW). Apparent quantum yields (ΦRI) up 10% 5% were measured for 1O2* respectively, which upper range previously reported values. This indicated that contain photosensitizers highly efficient at producing 3C*. ΦRI concentrations ([RI]ss) decreased MW due higher-MW molecules engaging charge-transfer interactions disrupt processes oxidant production. Machine learning models used understand predict based measurable optical chemical properties EPS. study provides new insights into bioaerosols can

Language: Английский

Citations

0
Formation and loss of light absorbance by phenolic aqueous SOA by ●OH and an organic triplet excited state DOI Creative Commons

Stephanie Arciva,

Lan Ma,

Camille Mavis

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(7), P. 4473 - 4485

Published: April 17, 2024

Abstract. Brown carbon (BrC) is an important component of biomass-burning (BB) emissions that impacts Earth's radiation budget. BB directly emits primary BrC as well gaseous phenolic compounds (ArOH), which react in the gas and aqueous phases with oxidants – such hydroxyl radical (⚫OH) organic triplet excited states (3C∗) to form light-absorbing secondary aerosol (SOA). These reactions atmospheric phases, cloud/fog drops liquid water (ALW), SOA (aqSOA), i.e., low-volatility, high-molecular-weight products. While these are routes aqSOA formation, light absorption lifetimes formed poorly characterized. To study aspects, we monitored formation loss by produced six highly substituted phenols ⚫OH 3C∗. parent absorb very little tropospheric sunlight, they oxidized can significant amounts sunlight. The extent depends on both ArOH precursor oxidant: more from rather than ⚫OH. Under laboratory conditions, extended reaction times experiments diminish sunlight timescales hours, while 3C∗ reduce much slowly. Estimated range 3 17 h drops, where major sink, 0.7 8 ALW, sink.

Language: Английский

Citations

3
Singlet oxygen is produced from brown carbon-containing cooking organic aerosols (BrCOA) under indoor lighting DOI Creative Commons
Nadine Borduas‐Dedekind, Keighan Gemmell,

Madushika Madri Jayakody

et al.

Environmental Science Atmospheres, Journal Year: 2024, Volume and Issue: 4(6), P. 611 - 619

Published: Jan. 1, 2024

Indoor BrC-containing cooking organic aerosols (BrCOA) can act as sensitizers generating the first excited state of molecular oxygen, singlet under indoor lighting conditions. Sustained oxygen steady-state levels lead to prolonged oxidation impacting air quality.

Language: Английский

Citations

3
Effects of Copper on the Chemical Kinetics and Brown Carbon Formation in the Aqueous ∙OH oxidation of Phenolic Compounds DOI
Junwei Yang,

Tianye Zhou,

Yuting Lyu

et al.

Environmental Science Processes & Impacts, Journal Year: 2024, Volume and Issue: 26(9), P. 1526 - 1542

Published: Jan. 1, 2024

Many phenolic compounds (PhCs) in biomass burning and fossil fuel combustion emissions can partition into atmospheric aqueous phases (

Language: Английский

Citations

2
Evaluating the secondary contribution of photosensitized chemistry to OH production in aerosols DOI Creative Commons

Emma A. Petersen-Sonn,

Marcello Brigante, Laurent Deguillaume

et al.

Environmental Science Atmospheres, Journal Year: 2024, Volume and Issue: 4(10), P. 1170 - 1182

Published: Jan. 1, 2024

This study explores the potential contribution of secondary production OH radicals in aerosols and cloud/fog conditions arising from brown carbon (BrC) triplet state chemistry.

Language: Английский

Citations

2
Complexities of Photosensitization in Atmospheric Particles DOI Creative Commons
Zhancong Liang, Yongjie Li,

Brix Raphael Go

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(11), P. 1333 - 1351

Published: Oct. 10, 2024

Brown carbons (BrCs) play a pivotal role in the light absorption by aerosol particulates exerting positive radiative forcing effect that contributes to global warming. Beyond impacts on balance, some BrCs, as photosensitizers, can generate reactive triplet-state molecules toward various atmospheric upon photoexcitation. The significance of photosensitization has been increasingly recognized, particularly context escalated wildfire incidents emit substantial BrCs. We focus complex discussing current challenges, including (1) diverse reactivities photosensitizer mixture particles, (2) methodologies for investigating processes, (3) driving factors photosensitization, and (4) typical pathways mechanisms photosensitized reactions. Lastly, we advise future research refined parametrization triplet singlet oxygen concentrations, alongside their reactivities.

Language: Английский

Citations

2