Researchers have engineered a novel material derived from wood, capable of capturing solar radiation, storing that energy as thermal heat, and subsequently continuing to generate electrical power even when daylight fades. This research demonstrates the feasibility of transforming commonplace timber into a condensed and environmentally sound foundation for solar-thermal energy applications.
The scientists started with balsa wood as their raw material, chosen for its inherent lightness and its natural network of fine microchannels. Lignin was first extracted from the wood to enhance its sponginess. Following this, the internal surfaces of these channels were coated with exceedingly thin layers of black phosphorene, a substance known for its excellent broadband light absorption capabilities. To safeguard this delicate coating from atmospheric degradation, it was encased within a shell composed of tannic acid and iron ions.
Subsequently, silver nanoparticles were incorporated into the structure to boost light absorption, and the exterior was rendered highly hydrophobic. The channels were then filled with stearic acid, a phase-change substance that liquefies upon heating, retains the amassed warmth, and subsequently releases it as it cools. The outcome is a robust, heat-storing composite material that maintains its performance characteristics even after numerous cycles of heating and subsequent cooling.
According to the research team, this system achieves an impressive conversion rate of up to 91.27% of solar energy into usable heat, stores roughly 175 kJ/kg, and can output up to 0.65 V when coupled with a thermoelectric generator. No significant decline in performance was observed even after enduring 100 heating and cooling repetitions.
The pertinent takeaway from the scientists is that this wooden substrate integrates several advantageous traits: flame retardancy, moisture resistance, microbe-fighting capabilities, and resilience against fouling, positioning it as an excellent candidate for exterior deployments. Looking ahead, materials crafted this way hold promise not only for solar energy capture but also for integration into electronics, construction elements, and self-sufficient power setups.
About the Author
