Singlet oxygen: Properties, generation, detection, and environmental applications

Yue Wang; Yan Lin; Shanying He; Shaohua Wu; Chunping Yang

doi:10.1016/j.jhazmat.2023.132538

Singlet oxygen: Properties, generation, detection, and environmental applications

J Hazard Mater. 2024 Jan 5:461:132538. doi: 10.1016/j.jhazmat.2023.132538. Epub 2023 Sep 13.

Authors

Yue Wang¹, Yan Lin², Shanying He³, Shaohua Wu⁴, Chunping Yang⁵

Affiliations

¹ College of Environmental Science and Engineering, Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou, Zhejiang 310012, China; College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China.
² College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China.
³ College of Environmental Science and Engineering, Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou, Zhejiang 310012, China. Electronic address: heshanying@zjgsu.edu.cn.
⁴ Academy of Environmental and Resource Sciences, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China. Electronic address: wushaohua@hnu.edu.cn.
⁵ College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China; Academy of Environmental and Resource Sciences, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China; School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, Jiangxi 330063, China. Electronic address: yangcp@zjgsu.edu.cn.

PMID: 37734310
DOI: 10.1016/j.jhazmat.2023.132538

Abstract

Singlet oxygen (¹O₂) is molecular oxygen in the excited state with high energy and electrophilic properties. It is widely found in nature, and its important role is gradually extending from chemical syntheses and medical techniques to environmental remediation. However, there exist ambiguities and controversies regarding detection methods, generation pathways, and reaction mechanisms which have hindered the understanding and applications of ¹O₂. For example, the inaccurate detection of ¹O₂ has led to an overestimation of its role in pollutant degradation. The difficulty in detecting multiple intermediate species obscures the mechanism of ¹O₂ production. The applications of ¹O₂ in environmental remediation have also not been comprehensively commented on. To fill these knowledge gaps, this paper systematically discussed the properties and generation of ¹O₂, reviewed the state-of-the-art detection methods for ¹O₂ and long-standing controversies in the catalytic systems. Future opportunities and challenges were also discussed regarding the applications of ¹O₂ in the degradation of pollutants dissolved in water and volatilized in the atmosphere, the disinfection of drinking water, the gas/solid sterilization, and the self-cleaning of filter membranes. This review is expected to provide a better understanding of ¹O₂-based advanced oxidation processes and practical applications in the environmental protection of ¹O₂.

Keywords: Advanced oxidation process; Free radical; Molecular oxygen; Non-radical species; Sterilization.

Publication types

Review