Photocuring technology strengthens thermal localization of interfacial solar-driven evaporator

Based on the principle of limited light penetration in porous foam, a layer of PDMS is photocured on the surface of foam evaporator, and the photothermal conversion layer is accurately hydrophobic encapsulated. Manufactured Janus cone foam evaporator with good thermal positioning capability and stable production of fresh water and salt. • Janus evaporator with photocured hydrophobic layer. • Enhanced durability and salt collection with conical-janus structure. • Photocurable PDMS for precise heat Utilization and Mineral Extraction Potential. Interfacial solar-driven vapor generation (ISVG) is a promising solution for water purification due to its low cost and environmental friendliness. However, when dealing with highly concentrated wastewater, problems such as salt crystallization and significant heat losses affect the continuous and efficient operation of the evaporator. By capitalizing on the restricted penetration depth of light within porous foam, an innovative photocuring technology was selected for the manufacturing of the Janus-like conical foam evaporator (JCFE). Via ultraviolet curing of polydimethylsiloxane (PDMS), hydrophobic encapsulation of the photothermal conversion layer was accomplished, consequently improving the precise positioning and utilization of the system’s thermal energy. On this basis, JCFE can operate stably in 21 wt% brine for 40 h, with an evaporation rate of about 1.69 kg m -2 h −1 , and the evaporator remains intact after removing surface salts. Furthermore, the evaporator demonstrates robust stability over a period of 14-days of utilization. This work promotes sustainable desalination technologies and presents a stable approach for achieving zero liquid discharge (ZLD) of high-salinity brine and the recovery of mineral resources from saltwater.