Enhanced removal of emerging contaminants from tap water by developing graphene oxide and nanoplatelet hybrid aerogels

Abstract

The removal of emerging contaminants (ECs) from drinking water is a current challenge of global concern. Graphene-based sorbents are attracting increasing interest in this field owing to the chemical versatility of graphene-based materials, their commercial availability and processability in various 3D structures. Herein, for the first time, graphene aerogels (GAs) are reported based on the synergy of graphene oxide (GO) and graphene nanoplatelets (GNPs) derived from waste tire and their use as a sorbent for a mixture of ECs in tap water. Reduction of GO up to 52.1% (O/C = 0.092) was demonstrated through X-ray photoelectron spectroscopy, whereas no changes in the GNP structure during aerogel synthesis were demonstrated with comprehensive spectroscopic and microscopic characterisation. Adsorption of a selection of ECs in a mixture from tap water was tested under flow conditions by inserting the aerogels into filtration cartridges and filtering tap water spiked with the mixture of ECs. Remarkably, the GO + GNP aerogel showed an increase in adsorption capacity of about 2.3 times that of the rGO aerogel owing to the higher obtained surface area, 27 instead of 16 m² g⁻¹, and the resultant more-reduced structure.