Transformation of graphene oxide affects photodegradation of imidacloprid in the aquatic environment: Mechanism and implication

Mengzhu Xue; Peiyao Li; Chang Li; Yonghao Qi; Zhentong Han; Jiarui Li; Ao Li; Tianjiao Xia

doi:10.1016/j.scitotenv.2023.163108

Transformation of graphene oxide affects photodegradation of imidacloprid in the aquatic environment: Mechanism and implication

Sci Total Environ. 2023 Jun 25:879:163108. doi: 10.1016/j.scitotenv.2023.163108. Epub 2023 Mar 30.

Authors

Mengzhu Xue¹, Peiyao Li¹, Chang Li¹, Yonghao Qi¹, Zhentong Han¹, Jiarui Li¹, Ao Li¹, Tianjiao Xia²

Affiliations

¹ College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
² College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China. Electronic address: tjxia@nwafu.edu.cn.

PMID: 37003175
DOI: 10.1016/j.scitotenv.2023.163108

Abstract

Graphene oxide (GO) is a representative novel carbonaceous nanomaterial, and neonicotinoid insecticides (NEOs) are currently the insecticides with the highest market share in the world. Their widespread application deservedly leads to their release to the environment. Thus, the complex interactions of these two types of organic compounds have attracted extensive attention. In this study, the effects of GO and its derivatives, reduced GO (RGO) and oxidized GO (OGO), on the photolysis of imidacloprid (IMD) (a typical NEO) under ultraviolet (UV) irradiation were systematically investigated. The results showed that the presence of the graphene-based nanomaterials (GNs) largely depressed the photodegradation of IMD, and the inhibition degree followed the order of RGO > GO > OGO. This was because the sp² π-conjugated structure in the GNs caused light-shielding effect and attenuated the direct photolysis of IMD, even though the GNs-generated reactive oxygen species (ROS) promoted the indirect photodegradation of IMD to a certain extent. Additionally, the rich O-functionalized GO and OGO altered the photolysis pathway of IMD and induced more toxic intermediate products. These results highlight the implication of carbonaceous nanomaterials on the behavior, fate and potential risk of NEOs in aqueous systems.

Keywords: Graphene oxide; Imidacloprid; Light-shielding effect; Photodegradation; Reactive oxygen species.