When Coordination Polymers Meet Wood: From Molecular Design toward Sustainable Solar Desalination

Solar-driven interfacial evaporation harnessing solarenergy ona water surface provides a sustainable and economic means to efficientlycapture freshwater from nontraditional water sources. Endowed witha hierarchical porous structure and mechanical stability, wood-basedevaporators represent a renewable alternative to petroleum-based materials.Nonetheless, incidental inferiorities of a low evaporation rate andweak interfacial strength are challenging to overcome. Herein, wepropose the usage of chemically stable coordination polymers (Ni-dithiooxamidato,Ni-DTA) as hydrophilic photothermal nanomaterials for the moleculardesign of robust wood-based evaporators with improved performance. In situ synthesis of Ni-DTA onto the channel wall of balsawoodprovides sufficient photothermal domains that localize the convertedenergy for facilitated interfacial evaporation. A rational controlof methanol/dimethylformamide ratios enables the coexistence of 1D-nanofibersand 0D-nanoparticles, endowing Balsa-NiDTA with a high evaporationrate of 2.75 kg m(-2) h(-1) and anenergy efficiency of 82% under one-sun illumination. Experimentaland simulation results reveal that Ni-DTA polymers with strong hydrationability decrease the equivalent evaporation enthalpy induced by decreasedH-bonding density of water molecules near the evaporation interface.The Balsa-NiDTA evaporator showed a high chemical stability, mainlydue to the robust Ni-S/Ni-N bonds and the superior celluloseaffinity of Ni-DTA. Furthermore, the Balsa-NiDTA evaporator showsan excellent antibacterial activity and low oil-fouling propensity.This work presents a facile and mild strategy to design chemicallystable wood-based evaporators, contributing to highly efficient andsustainable solar desalination under harsh conditions.