Reduced graphene oxide aerogel (RGO aerogel) is successfully synthesized via simultaneous reduction and self-assembly of graphene oxide (GO) sheets under gamma-ray irradiation. As the resulting RGO aerogel possesses an interconnected macroporous structure with strong hydrophobicity and oleophilicity, it has great potential in oil water separation. Adsorption distillation and adsorption-combustion are both utilized to treat oil floating on water or oil sinking below the water surface. More importantly, a simple device has been developed to adsorb continuously and collect floating oil, and it has shown great promise for practical application.