A protocol to study microdroplet photoreaction at an individual droplet level using in situ micro-Raman spectroscopy

Li, Kejian; Wang, Longqian; Liu, Juan; Gong, Kedong; Wang, Wei; Ge, Qingjie; Liu, Yangyang; Zhang, Liwu

doi:10.1016/j.xpro.2022.101704

Cited by 3 publications

(4 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The temperature during the photoreaction was kept at 25 ± 2 °C by an electric fan. After light irradiation (365 nm UV lamp, ∼ 2.6 mW cm –2 ), the microdroplets were collected with a coverslip . Then, a specific amount of the collected solution was taken by a pipet, diluted quantitatively using 0.1 M HCl, and filtered through a 0.22 μm PTFE membrane filter for further analyses.…”

Section: Methodsmentioning

confidence: 99%

Significantly Accelerated Hydroxyl Radical Generation by Fe(III)–Oxalate Photochemistry in Aerosol Droplets

Wang

Liu

et al. 2023

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

Fe(III)–oxalate complexes are ubiquitous in atmospheric environments, which can release reactive oxygen species (ROS) such as H2O2, O•2–, and OH• under light irradiation. Although Fe(III)–oxalate photochemistry has been investigated extensively, the understanding of its involvement in authentic atmospheric environments such as aerosol droplets is far from enough, since the current available knowledge has mainly been obtained in bulk-phase studies. Here, we find that the production of OH• by Fe(III)–oxalate in aerosol microdroplets is about 10-fold greater than that of its bulk-phase counterpart. In addition, in the presence of Fe(III)–oxalate complexes, the rate of photo-oxidation from SO2 to sulfate in microdroplets was about 19-fold faster than that in the bulk phase. The availability of efficient reactants and mass transfer due to droplet effects made dominant contributions to the accelerated OH• and SO4 2– formation. This work highlights the necessary consideration of droplet effects in atmospheric laboratory studies and model simulations.

show abstract

Section: Methodsmentioning

confidence: 99%

Significantly Accelerated Hydroxyl Radical Generation by Fe(III)–Oxalate Photochemistry in Aerosol Droplets

Wang

Liu

et al. 2023

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

show abstract

“…When the temperature exceeds 100 °C, the evaporation of water in microdroplets is more complete, and the heat is mainly applied to accelerate the reactions. 36 Other in situ characterization methods include Raman spectroscopy, 37 fluorescence spectroscopy, 14 and stimulated Raman excited fluorescence microscopy 21 of individual microdroplets deposited on a hydrophobic surface. It is worth mentioning that stimulated Raman excited fluorescence microscopy was also utilized to measure the electric field at the surface of microdroplets.…”

Section: Characterization Methodsmentioning

confidence: 99%

The Spontaneous Electron-Mediated Redox Processes on Sprayed Water Microdroplets

Jin

Chen

et al. 2023

JACS Au

View full text Add to dashboard Cite

Water is considered as an inert environment for the dispersion of many chemical systems. However, by simply spraying bulk water into microsized droplets, the water microdroplets have been shown to possess a large plethora of unique properties, including the ability to accelerate chemical reactions by several orders of magnitude compared to the same reactions in bulk water, and/or to trigger spontaneous reactions that cannot occur in bulk water. A high electric field (∼109 V/m) at the air–water interface of microdroplets has been postulated to be the probable cause of the unique chemistries. This high field can even oxidize electrons out of hydroxide ions or other closed-shell molecules dissolved in water, forming radicals and electrons. Subsequently, the electrons can trigger further reduction processes. In this Perspective, by showing a large number of such electron-mediated redox reactions, and by studying the kinetics of these reactions, we opine that the redox reactions on sprayed water microdroplets are essentially processes using electrons as the charge carriers. The potential impacts of the redox capability of microdroplets are also discussed in a larger context of synthetic chemistry and atmospheric chemistry.

show abstract

“…The details can be found in our previous study. 35 To avoid the impact of gas−liquid interface concentration enrichment of PFOA on microdroplet generation, the solution in nebulizer was mixed by 1 min oscillation before immediate spraying. The bulk phase reaction was carried out using a miniature beaker containing 5 mL solution with a thickness of ∼15 mm, and the top was covered with a quartz plate (Figure S4b).…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

“…After microdroplet generation, the quartz wafer was sealed into a custom-designed reaction chamber (Figure S4a) under high relative humidity conditions (RH > 93%). The details can be found in our previous study . To avoid the impact of gas–liquid interface concentration enrichment of PFOA on microdroplet generation, the solution in nebulizer was mixed by 1 min oscillation before immediate spraying.…”

Section: Materials and Methodsmentioning

confidence: 99%

Significantly Accelerated Photochemical Perfluorooctanoic Acid Decomposition at the Air–Water Interface of Microdroplets

Li,

You,

Wang

et al. 2023

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

A protocol to study microdroplet photoreaction at an individual droplet level using in situ micro-Raman spectroscopy

Cited by 3 publications

References 15 publications

Significantly Accelerated Hydroxyl Radical Generation by Fe(III)–Oxalate Photochemistry in Aerosol Droplets

Significantly Accelerated Hydroxyl Radical Generation by Fe(III)–Oxalate Photochemistry in Aerosol Droplets

The Spontaneous Electron-Mediated Redox Processes on Sprayed Water Microdroplets

Significantly Accelerated Photochemical Perfluorooctanoic Acid Decomposition at the Air–Water Interface of Microdroplets

Contact Info

Product

Resources

About