Generation and identification of 1O2 in catalysts/peroxymonosulfate systems for water purification

Qianzhen Fang; Hailan Yang; Shujing Ye; Peng Zhang; Mingyang Dai; Xinjiang Hu; Yanling Gu; Xiaofei Tan

doi:10.1016/j.watres.2023.120614

Generation and identification of ¹O₂ in catalysts/peroxymonosulfate systems for water purification

Water Res. 2023 Oct 15:245:120614. doi: 10.1016/j.watres.2023.120614. Epub 2023 Sep 11.

Authors

Qianzhen Fang¹, Hailan Yang², Shujing Ye³, Peng Zhang⁴, Mingyang Dai², Xinjiang Hu⁵, Yanling Gu⁶, Xiaofei Tan⁷

Affiliations

¹ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen 518055, PR China.
² College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China.
³ School of Resources, Environment and Materials, Guangxi University, Nanning 530004, PR China.
⁴ State Key Laboratory of Hydraulics and Mountain River Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China.
⁵ College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China.
⁶ College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, PR China.
⁷ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China; Shenzhen Research Institute of Hunan University, Shenzhen 518055, PR China. Electronic address: tanxf@hnu.edu.cn.

PMID: 37717327
DOI: 10.1016/j.watres.2023.120614

Abstract

Catalysts for peroxymonosulfate (PMS) activation are appealing in the purification of organic wastewater. Singlet oxygen (¹O₂) is widely recognized as a crucial reactive species for degrading organic contaminants in catalysts/PMS systems due to its adamant resistance to inorganic anions, high selectivity, and broad pH applicability. With the rapid growth of studies on ¹O₂ in catalysts/PMS systems, it becomes necessary to provide a comprehensive review of its current state. This review highlights recent advancements concerning ¹O₂ in catalysts/PMS systems, with a primary focus on generation pathways and identification methods. The generation pathways of ¹O₂ are summarized based on whether (distinguished by the geometric structures of metal species) or not (distinguished by the active sites) the metal element is included in the catalysts. Furthermore, this review thoroughly discusses the influence of metal valence states and metal species with different geometric structures on ¹O₂ generation. Various potential strategies are explored to regulate the generation of ¹O₂ from the perspective of catalyst design. Identification methods of ¹O₂ primarily include electron paramagnetic resonance (EPR), quenching experiments, reaction in D₂O solution, and chemical probe tests in catalysts/PMS systems. The principles and applications of these methods are presented comprehensively along with their applicability, possible disagreements, and corresponding solutions. Besides, an identifying procedure on the combination of main identification methods is provided to evaluate the role of ¹O₂ in catalysts/PMS systems. Lastly, several perspectives for further studies are proposed to facilitate developments of ¹O₂ in catalysts/PMS systems.

Keywords: (1)O(2); Catalysts; Generation pathways; Identification methods; PMS system.

Publication types

Review