Advanced graphene nanosheets approaches to efficient solar thermal water purification system

Abstract

Water pollution is destroying natural resources and the water scarcity is the biggest challenge for scientist. Cleaning of water by using solar energy is an eco-friendly, economical and a long-term approach for water scarcity and pollution. Recently, graphene oxide (GO) achieved great interest due to its excellent physical and chemical properties. Graphene meets the requirements of excellent porousness, enhanced light absorption, and high photothermal transductions, which can be used to attain efficient production of clean water. In this work, advanced graphene nanomembranes have been used for the efficient production of clean water by utilizing solar thermal energy. In this context, synthesis of graphene is important for research and industrial applications. The graphene nanomembranes were prepared via a chemical exfoliation approach, which included the chemical oxidation of the graphite powder followed by utilization of concentrated sulfuric acid and nitric acid. Oxidized graphite powder was thermally annealed at [Formula: see text]C for 60 min to synthesize graphene oxide (GO). Chemical reduction of GO with H2O2 led to formation of rGO. Moreover, scanning electron microscopic (SEM) results confirm that the rGO layer of about 70 nm has been synthesized. X-ray diffraction, EDX, and UV–Vis spectroscopic investigations demonstrated the crystallinity, elemental composition, and absorbance of the synthesized material, respectively. Furthermore, graphene nanomembranes have achieved an average water evaporation rate of 6.26 kg m[Formula: see text] h[Formula: see text] under 4 sun illumination with an efficiency of 94.1%.