N-doped graphene/carbon hybrid aerogels for efficient solar steam generation

Efficient solar-thermal energy conversion is critical for utilization of abundant solar energy in solar power-based concentration systems, photochemical plants and seawater desalination technologies, etc. However, conventional processes for solar steam generation generally rely on high-temperature heating of bulk liquids, which requires highly concentrated solar energy and suffers from high energy and optical losses. Therefore, it is still critical to explore and design solar absorption materials with high solar-thermal conversion efficiency. Herein, we report the preparation of a nitrogen-doped graphene/carbon hybrid aerogel (NGCA) using graphene oxide (GO) and melamine form (MF) for highly efficient solar steam generation by a simple dip-coating processes, air drying and carbonization at different temperatures. The NGCA carbonized at 600 degrees C (NGCA-600) exhibits excellent stability, efficient light absorption, good hydrophilicity for water supply and abundant micro-pores for vapor escape, therefore, it can achieve 90% solar-thermal conversion efficiency under the light density of 1 kW m(-2). This cost-effective and reusable solar-thermal convertible material could be ideal for practical applications in seawater desalination, water purification and sterilization. (C) 2018 Elsevier Ltd. All rights reserved.