An acid induction strategy to construct an ultralight and durable amino-functionalized graphene oxide aerogel for enhanced quinoline pollutants extraction from coking wastewater

Abstract The direct emission of quinoline in coking wastewater has great harm to human health and environmental quality. Therefore, it is urgent to develop advanced materials for efficient adsorption of quinoline in wastewater. In this study, a novel three-dimensional amino-functionalized graphene oxide aerogel (MGOA) was prepared by an acid induction strategy, which triggers the esterification and amidation of graphene oxide (GO) nanosheets and ammonium citrate. This strategy not only improves the chemical stability and mechanical strength of as-prepared MGOA, but also provides a large number of effective adsorption sites to achieve the efficient adsorption towards quinoline. MGOA has the advantages of three-dimensional interconnected hierarchical pore structure, large specific surface area, and low density. When the initial quinoline concentration is 50 mg L-1, the adsorption capacity (qe) of MGOA towards quinoline is as high as 103 mg g-1 at 298 K. More importantly, in the column adsorption system, the distribution coefficient (PC) at 10% breakthrough is 14.16 mg g-1 μM-1, which is the highest level yet reported. MGOA exhibits good reusability and outstanding solid-liquid separation advantage during eight adsorption-desorption cycles. Density functional theory and van der Waals surface electrostatic potential were used to investigated the adsorption behavior of quinoline on aerogel. The binding force between MGOA and quinoline molecule is strong, with an adsorption energy up to -78.68 kJ mol-1. Thus, MGOA is considered as a promising candidate for removing quinoline contaminants from aqueous solutions.