All-Day, All-Weather Desalination Using a Contactless Evaporator with Antisalt Fouling Property
Higgins M. Wilson, Tawseef Ahmad Wani, Sang Joon Lee
Abstract
Interfacial solar steam generation (ISSG) technology provides a promising solution to the global issue of freshwater scarcity. However, its practical application is hindered by salt fouling and inconsistent solar illumination. In this work, a novel interfacial solar steam generator is proposed that integrates contactless design with low-voltage joule heating to provide all-day, all-weather freshwater generation. The contactless design utilizes a solar-reduced graphene oxide coated carbon fabric (SRGO–CF) as a heat generator and super hydrophilic paper walls as water transport channels. The contactless device can generate steam at the maximum rate of 4.27 kg m –2 h –1 under 1 sun solar illumination and small input voltage due to the excellent photothermal and electrothermal capabilities of SRGO–CF. At an input voltage of 2.5 V, the SRGO–CF evaporator exhibits an evaporation rate of 3.52 kg m –2 h –1 and 2.32 kg m –2 h –1 for 3.5 wt % salt water respectively with and without 1 sun illumination for a long period of time without any salt fouling, demonstrating its all-day, all-weather capability. The proposed contactless ISSG evaporator can resolve the impractical issue of conventional ISSG-based evaporators owing to irregular weather conditions and salt fouling issues while also promoting zero liquid discharge-based salt harvesting.