Preparation of Reduced Graphene Oxide-based Melamine Sponge and Its Absorption Properties

Graphene oxide (GO) was synthesized via the Hummers method and ultrasonic stripping method using the natural graphite as raw materials. Furtherly, reduced graphene oxide-based melamine sponges (RGOME) were fabricated via a dip-coating method which were post-reduced online. As-prepared RGOME sponges were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and optical contact angle measuring apparatus. Oil adsorption capacity, the oil/water selective adsorption and reusability of the RGOME sponges were also studied. The results demonstrate that the RGOME sponges exhibit good hydrophobicity and superoleophilicity, and oil adsorption capacity is up to 56-127 g/g. The adsorptive process of oils, like toluene and kerosene, was fitted to the Bangham equation for the isothermal adsorption. In terms of selective adsorptive process, the concentration of oil in oil-water mixture decreased drastically, while oil adsorption capacity constantly increased. The resulting separation efficiency was up to 74.49%, and as-prepared sponges have better performance for oil/water separation than other sorbents reported in the literature. In addition, the RGOME sponges can be reused more than 10 times with gently deteriorating in adsorption capacity.