Development of a Highly Efficient 3D Core‐Shell Evaporator for Sustainable Desalination

The development of effective, sustainable materials for salinity water desalination is essential for addressing worldwide water scarcity. This study presents the development of a portable core‐shell evaporator utilizing cellulose pulp bound with polyvinyl alcohol (PVA) as the adhesive matrix, combined with a molybdenum disulphide/graphene (MoS 2 /G, 1:1) photothermal layer. PVA enhances the structural integrity, versatility and uniformity of water dispersion within the cellulose core. The evaporator is produced using a freeze‐drying technique that preserves the porous structure, improves water transport channels and maintains the integrity of the photothermal coating. The hydrophilic cellulose–PVA core facilitates rapid water delivery and sustained evaporation, whereas the MoS 2 /G shell ensures efficient light absorption, localized thermal retention and reduced thermal dissipation. Augmenting MoS 2 /G content (2%–6%) markedly improves performance. Under solar irradiation, the 6% MoS 2 /G evaporator attains an evaporation rate of 2.35 kg m −2 h −1 with a solar‐to‐vapour efficiency of 95%.