Janus Structured Solar Evaporator with Intrinsic Salt Resistance towards High-Efficient Desalination

Utilizing inexhaustible solar energy and seawater resources, solar-driven interfacial steam generation (SSG) offers a straightforward and efficient solution to freshwater scarcity and wastewater reuse. The present study provides a seawater desalination strategy through carbon nanotubes/thermoplastic polyurethane/polydimethylsiloxane (CNTs/TPU/PDMS) composite sponge. This material is engineered for enhanced solar-driven interfacial evaporation, explicitly targeting the mitigation of salt deposition which is detrimental to the efficiency of traditional solar evaporator. Using a commercially available melamine sponge as the base structure, an impregnation-drying technique was adopted for the optimization of light absorber CNTs. The formation of a Janus structure by incorporating a composite layer of PDMS, melamine sponge, and CNTs enhances the salt resistance and water transport capability of the evaporator. Owing to light absorption properties and Janus structure, a maximal evaporation rate of 5.02 kg m- 2 h- 1, with a sustained average rate of 4.8 kg m- 2 h- 1, as well as proficient ion rejection and organic dye purification efficacy was achieved.