Graphene-Based Stand-Alone Networks for Efficient Solar Steam Generation
Jie Tian, Xiaohui Huang, Wei Wu
Abstract
Solar steam generation is one of the promising methods to obtain freshwater from wastewater and saline water. Here, using graphene/graphene oxide composite nanosheets and polyvinyl alcohol as raw materials, hydrophilic and porous graphene composite (GGOP) with good toughness was prepared by a one-step hydrothermal method. GGOP exhibited high and wide light absorbance (94.5% from 250 to 2200 nm wavelength), abundant porous structures (high porosity of 97.2%), low thermal conductivity (0.02 W m–1 K–1), and low density (0.011 g cm–3). When GGOP was used as a solar steam generator, it delivered a water evaporation rate of 1.44 kg m–2 h–1 and a solar–thermal conversion efficiency of 86% under 1 kW m–2 irradiation. Moreover, it was also confirmed that GGOP maintained a stable performance for solar steam generation even after 10 cycles. Our results demonstrate that graphene/graphene oxide composite nanosheets have a good prospect in solar steam generation.