rGO coated cotton fabric and thermoelectric module arrays for efficient solar desalination and electricity generation

Abstract

One promising solution to the freshwater crisis is solar-driven interfacial evaporation-based desalination. However, an alternate strategy is needed to address both water and energy shortages in parallel. Additionally, the disposal of desalination brine necessitates specific consideration while designing a sustainable solar interfacial desalination system. Herein, we demonstrate a single system that utilizes incident solar irradiance to produce interfacial steam using reduced graphene oxide (rGO) coated cotton fabric (CF) to desalinate seawater with an evaporation efficiency of 86.98%. The high thermal conductivity and excellent optical absorption of rGO contribute to the absorption of a broad solar spectrum. The system also produces 339.26 mW of electricity simultaneously by deploying commercially available thermoelectric generator (TEG) modules that use the squandered heat, increasing the overall system efficiency by 7.3%. The use of a custom-made power electronics module ensures operating at the maximum power point which has also been verified by computer simulation. Finally, hydrogen gas with zero carbon emission is produced by electrolyzing the seawater utilizing the electricity generated by the TEG module using solar-induced heat at a rate of 0.52 mmol h⁻¹. Converting brine into hydrogen and oxygen gas by electrolysis demonstrates a potential in situ approach for desalination waste remediation.