Bifunctional Material with Organic Pollutant Removing and Antimicrobial Properties: Graphene Aerogel Decorated with Highly Dispersed Ag and CeO₂ Nanoparticles

Abstract

The graphene aerogels supporting Ag and CeO2 nanoparticles (NPs) (Ag/CeO2/GA) with bifunctional performances have been fabricated by a modified gelatinization reaction method. Through the control of GO concentration and ultrasonic-assisted prereduction process, the small NPs can be dispersed highly into the porous structure of GA. The integration of a hierarchical porous structure and a synergistic effect between CeO2 and Ag NPs grant them bifunctional properties of organic pollutant removing (100% of methylene blue and 81.8% of bisphenol A were degraded within 12 min and 4 h, respectively), and antimicrobial activity against Escherichia coli (MIC100%Ag = 7.5 ppm; MBC100%Ag = 11.3 ppm). The possible mechanism is the improved photocatalytic performance of CeO2/GA by a unique surface plasmonic effect of Ag NPs due to increasing light absorption and photoconductivity for photoexcited holes and electrons. Therefore, the holes and radicals (especially •OH) can be produced continuously and efficiently from Ag/CeO2/GA, which can remove organic pollution from water efficiently, while protecting the water from bacterial pollution. Moreover, a good recycling stability and biocompatibility suggest that such bifunctional material has a great promise in water purification applications.