Accessible Graphene Aerogel for Efficiently Harvesting Solar Energy

Abstract

Solar steam generation through heat localization is a new approach to efficiently utilize solar energy. Nanocomposites with noble metals and other porous materials have been employed to generate solar vapor at a high light intensity. However, large-scale applications of the nanocomposites based on noble metals are restricted due to their high cost, complex preparation, and low recycling stability. Herein, we report a simple method toward fabricating graphene aerogel (GA) from graphene oxides only by photoreduction, which is for the first time used to harvest solar energy. GA can not only convert almost the entire incident solar light to heat energy but can also self-float on the surface of water and pump the interface water forming a constant water steam. Solar steam generation efficiencies of 53.6 ± 2.5% and 82.7 ± 2.5% are achieved at light intensities of 1 and 10 kW m –2, respectively. Furthermore, this efficiency is still kept at a high value, and the morphology of GA is hardly broken after 10 cycles of testing. This technology of steam generation through efficiently harvesting solar energy is highly promising for sterilization of waste and seawater desalination.