Photoreactivity of graphene oxide in aqueous system: Reactive oxygen species formation and bisphenol A degradation

• Published in: Chemosphere (Oxford) Vol. 195; pp. 344 - 350
• Main Authors: Adeleye, Adeyemi S., Wang, Xinzhe, Wang, Fanglu, Hao, Rongjie, Song, Weihua, Li, Yao
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2018
• Subjects: Bisphenol A; Graphene oxide; Photoactivity; Reactive oxygen species; Transformation; Bisphenol A; Reactive oxygen species; Transformation; Graphene oxide; Photoactivity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2017.12.095

The phototransformation and environmental implications of graphene oxide (GO) have been widely studied in order to understand its implications upon release into the environment. However, very little is known about the formation of reactive oxygen species (ROS) by GO under solar irradiation. Currently there are no studies on the mechanism of ROS formation by GO or the amount of ROS catalyzed by the nanomaterials in the environment. In this study, we carefully investigated the different types and formation mechanisms of ROS generated by GO in the presence of simulated solar irradiation. The effect of GO's photoactivity on bisphenol A (BPA), a representative organic co-pollutant, was also studied. The conduction band electron (eaq−) of GO led to the formation of different ROS including OH, O2–, and 1O2. Among the three types of ROS investigated, O2– was the most abundant species generated during simulated solar irradiation of GO. BPA was degraded, mainly due to the oxidative potential of the valence band holes produced during solar irradiation of GO. This study advances understanding of the photoactivity of GO and its potential impact on other possible environmental co-pollutants. [Display omitted] •OH, O2–, and 1O2 were generated upon the solar irradiation of GO and rGO.•The co-occurrence of hvb+ and eaq− transients upon the irradiation of GO.•BPA was degraded by the valence band holes produced during solar irradiation of GO.•Direct photolysis of BPA and reactions with 1O2 O2– or OH were of lesser importance.