Chitosan/reduced graphene oxide-modified spacer fabric as a salt-resistant solar absorber for efficient solar steam generation

Abstract

Solar steam generation by direct harvesting of light irradiation has emerged as one of most efficient technologies for utilization of solar energy and production of fresh water. Herein, we report the fabrication of a novel solar steam generation system based on a blank hollow spacer fabric (BHSF) prepared by filling spaces with chitosan and coating with reduced graphene oxide on the surface. Based on its porous textile fabric structure, with excellent thermal insulation, the modified BHSF shows better performance for water transport and mechanical properties, with a compression strength of up to 733 kPa at 70% strain and low thermal conductivity (0.08 W m⁻¹ K⁻¹). Under solar light power of 1 kW m⁻², this solar generator gives an evaporation efficiency of 86%, which is comparable to the best performance for multilayer systems that have been reported so far. More significantly, the unique hollow structure of BHSF, with an aligned big channel array (2 mm in size), which provided additional low-tortuosity pathways, endows the modified BHSF with excellent salt-resistant properties, such as evaporation in high saline solution. Such a textile-based BHSF may hold great potential for scalable manufacture of a cost-efficient solar still with excellent mechanical flexibility, physicochemical robustness and high solar energy conversion efficiency for a variety of applications, including power generation, desalination, and steam sterilization.