Volumetric solar steam generation enhanced by reduced graphene oxide nanofluid

Abstract Solar steam generation is a highly efficient photo-thermal conversion method that has a wide range of applications in water purification, distillation, power plants, and seawater desalination. Low steam generation efficiency was obtained for solar steam generation using traditional working media. Therefore, reduced graphene oxide (rGO) nanofluids with good stability and light absorption capability were fabricated to achieve highly efficient volumetric solar steam generation in this work. The effects of rGO mass concentration and light intensity on solar steam generation enhancement were investigated experimentally. It was found that a hot area was formed at water–air interface due to the unique lamellar structure of rGO with good light absorption characteristic, and sunlight was absorbed by the hot area to generate steam locally, which reduced thermal loss and improved evaporation efficiency. The solar steam generation enhancement achieved by the rGO nanofluids reduced evaporation costs and expanded their applicability in seawater desalination, clean water production, sterilization of waste, etc.