Reconstitution of woody biomass framework via dual-functional lignin engineering toward efficient and salt-resistant solar desalination

Solar-driven interfacial evaporation is a promising solution to address global freshwater scarcity, with woody biomass-based evaporators standing out for their sustainability and cost-effectiveness. However, current woody biomass-based systems often suffer from inefficient water management and suboptimal photothermal performance. Herein, we develop a dual-function lignin-engineered reconstituted wood framework strategy, achieving both compositional and structural optimization of woody biomass to enhance its evaporation performance via water management and thermal management. By partially retaining and reconfiguring lignin within the woody biomass framework, a higher fraction of loosely bound "intermediate water" with reduced evaporation enthalpy is generated while preserving the water-pumping capability. Concurrently, the extracted lignin is upcycled via laser-induced graphitization into a broadband photothermal layer composed of hierarchical graphene/graphitic carbon structures with solar absorptivity exceeding 95%. This synergistic design results in the E-150 solar evaporator, which achieves an evaporation rate of 2.24 kg m⁻² h⁻¹ and a photothermal conversion efficiency of 91.52% under one-sun irradiation, surpassing most reported wood-based evaporators. Moreover, the retained lignin sustains multiscale channel integrity, imparting strong salt resistance, high recyclability, and robust purification capabilities. This integrated biomass valorization strategy provides a scalable, low-cost, and eco-friendly route for high-performance solar desalination and sustainable water-energy applications.