Marine biomass-derived PDMS-based composite sponge for sustainably sourced solar-driven interfacial evaporation

Solar-driven interface evaporation has emerged as an attractive technology for addressing the pressing issue of water scarcity. Herein, from the perspective of utilizing and managing ocean resources, we have developed a comprehensive evaporator based on ocean biomass for efficient solar-driven interfacial evaporation, aiming to sustainably harness marine resources. The construction of a biomass-based evaporator was achieved using three-dimensional melanin nanoparticles (MNPs)@carboxymethyl chitosan (CMCS)/polydimethylsiloxane (PDMS) porous sponge, which exhibits highly hydrophilic and porous properties. In this study, MNPs functioned as the photothermal material and the CMCS-hydrophilic modified PDMS sponge was utilized as the supportive material. Owing to its outstanding photothermal conversion capability and ingeniously designed columnar shape with cold evaporation surface, the MCP sponge-based evaporator achieves a water evaporation rate of 2.04 kg·m−2·h−1 and an evaporation efficiency of 85% under 1sun illumination. In addition, the MCP sponge-based evaporator exhibits an outstanding desalination performance (93% salt rejection) and purification efficiency for dyes with natural sunlight. This groundbreaking study presents an innovative method by utilizing marine biomass-derived CMCS and MNPs as raw materials to construct a high-performance solar-driven interface evaporator, thereby tackling clean water generation and promoting the sustainability of marine ecosystems.