Evaporation‐Driven Dual‐Function Wood Composites: Integrating Hydrovoltaic Generation and Thermal Management in Architectural Applications

Natural materials, prized for their hierarchical microchannels, eco-friendliness, and low cost, show great promise for evaporation-driven power generation. Yet developing them into bifunctional platforms that simultaneously produce electricity and cooling remains an unmet challenge. This study demonstrates a biomass-based dual-functional platform using chemically modified metasequoia wood for concurrent electricity generation and evaporative cooling. The wood's vertically aligned microchannels enable anisotropic water transport, integrating carboxylation-modified structure with stainless steel electrodes to form a green energy device. In deionized water, it delivers ≈265.8 mV open-circuit voltage, ≈4.3 µA short-circuit current, and a record ≈408 µW m^- ² power density-beyond state-of-the-art biomass harvesters constructed via interface engineering. Its stable, adaptable performance across environments is further enhanced by circuit integration. Under solar radiation, an energy-saving cabin prototype achieves ≈6.1 °C cooling (≈857.5 W m^- ²) and maintains ≈2.1 °C night-time temperature reduction. A proof-of-concept, a metasequoia wood cabin prototype, generates power and cools simultaneously. Yangzhou tests show ≈1580-1630 mV output and ≈4.9 °C/1.1 °C day/night cooling, proving sustainable architecture viability. This work innovates sustainable energy-water technologies, enabling off-grid power and passive cooling for self-sufficient architectures.