Oil adsorption performance of graphene aerogels

Abstract

Graphene aerogels with different pore sizes, volumes and degrees of reduction were prepared through Pickering emulsion method. The controllable preparation of aerogels was achieved. The graphene aerogels prepared were characterized by FTIR and XPS. The adsorption capacity of pure oil by graphene aerogel was investigated. The graphene aerogels can adsorb pure oil quickly and hardly adsorb water. Linear relation exists between saturated adsorption capacities of graphene aerogels on oil and the densities of the oil adsorbed. The volume of the adsorbed organics on unit mass of the aerogel is 186.46 cm3 g−1. The occupancy rate in the aerogel pores is 73.71%. The factors affecting its adsorption rate on emulsified oil were investigated. The adsorption curves of graphene aerogels on emulsified oil conform to the pseudo-second-order kinetic model. The larger the inner diameter of the pore size in the graphene aerogels and the larger the outer surface area, the faster the adsorption rate of the emulsified oil would be. The adsorption rate of the rough internal with higher hydrophobicity decreases slightly, but as the degree of reduction increases, the hydrophobicity gradually increases and the adsorption rate increases gradually, so there should exist an optimum hydrophobicity value of aerogels for the adsorption of emulsified oil in water.