▎ 摘　　要

Carbon-based composites have gained renewed research interest in solar steam generation due to their low cost, durability and high photo-thermal efficiency. However, large-scale applications of carbon-based composites are restricted due to their high-emissivity in a high temperature condition. Here, by using melamine and graphene oxide as raw materials, the protonated g-C3N4/graphene hybrid hydrogel is prepared via a simple hydrothermal co-assembly method. The obtained self-floating hydrogel can convert the most of solar energy into thermal energy as well as pumping the underneath water to produce steam continuously. Furthermore, the existence of protonated g-C3N4 decreases the emissivity of the composites. As a result, an average evaporation rate of 4.11 kg m(-2)h(-1) and a superb solar steam generation efficiency of 94.5% under 3-sun illumination are achieved. This hybrid hydrogel is highly promising to provide a solution to enhance solar water evaporation and desalination performance. (C) 2019 Elsevier B.V. All rights reserved.