Salt resistant green graphene foam for solar energy conversion: Energy and economic analysis

Abstract

The growing scarcity of clean water, driven by population growth and climate change, calls for sustainable and cost-effective solutions in the current global context. Materials like graphene, known for their unique properties, have attracted significant attention. This study employed a green approach to synthesise highly porous and flexible oxidized graphene foam (OGF) derived from waste materials for enhancing interfacial evaporation and freshwater production from saline water using solar energy. This was achieved by modifying a conventional solar still (CSS) with OGF foam. Results show that the modified solar still (MSS) efficiently converts solar energy into heat, accelerating both the rate of evaporation and condensation. The average surface water temperature in the MSS was 2.64 times higher than in CSS, highlighting its superior heat retention capacity. Thermal studies showed a significant increase in energy conversion, leading to a 93.80 % increase in freshwater generation in the MSS. An energy-economic study revealed that the MSS has 1.95 times higher energy savings compared to CSS. Furthermore, the cost of freshwater production in the modified solar still is 1.54 times lower than the CSS, making it more economically viable solution. This eco-friendly and cost-effective graphene-based foam shows excellent potential in seawater desalination.