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

Abstract

Abstract 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.