Graphene oxide (GO) was prepared by an improved Hummers-Offeman's method. The GO and carboxylated multi-walled carbon nanotubes (CNTs-COOH) was used as raw materials

polyvinyl pyrrolidone (PVP) as crosslinking agent and ethylenediamine (EDA) as the reducing agent. Hydro-thermal method was adopted in the preparation of carbon nanotubes-graphene aerogel (CGA). The density was between 8.40 mg·cm-3 and 14.42 mg·cm-3 for CGAs under different mass ratios of GO to CNTs-COOH. The mechanical strength of the composite aerogel under the mass ratio of GO:CNTs-COOH=3:1 is optimal. The characterized results by scanning electron microscopy (SEM)

X ray diffraction (XRD)

X ray photoelectron spectroscopy (XPS) showed that GO and CNTs-COOH have been successfully assembled into reducing porous aerogel structure. The study on CGA sample adsorption characteristics of emulsified diesel oil in water at different temperatures showed that the adsorption capacity of CGA increased rapidly in the first 6 min. The adsorption equilibrium was achieved in about 30 min. With the increase of temperature

the equilibrium adsorption capacity increased gradually. The adsorption process follows pseudo-second order kinetics model. The apparent activation energy is 7.10 kJ·mol-1. Through the particle diffusion model analysis

it is found that the adsorption process of CGA is divided into an outer surface adsorption and pore adsorption processes

which include large inner pore adsorption

mesopore adsorption and small-size pore adsorption.