Oxygen plasma treated graphene aerogel as a solar absorber for rapid and efficient solar steam generation

Using optical absorption materials to heat localized water gaining water steam is a highly efficient way of solar energy utilization. Here, we introduced a new solar absorber of modified graphene aerogel (MGA) prepared by one-step hydrothermal method and oxygen plasma treatment for rapid and efficient solar steam generation. The obtained MGA possesses interconnected 3D porous networks formed by randomly construction of reduced graphene oxide (rGO) sheets and hydrophilic surface due to effective oxygen implant by oxygen plasma. Furthermore, under one sun illumination, MGA exhibited a high evaporation efficiency of 76.9%, which is not only due to the intrinsic property of rGO with excellent light absorption but also attributed to the particular structural merits of MGA-hydrophilic surface for water supplying and connected networks for steam escaping as well as porous matrix with low thermal conductivity. The cyclic tests confirmed that MGA still maintained a stable performance of solar steam generation even when it repeated multiple times. This new assembly demonstrated here is efficient and reusable for applications in rapid solar seawater desalination and wastewater treatment in remote area. (c) 2018 Elsevier Ltd. All rights reserved.