Hierarchical-Morphology Lignocellulosic Thermostat for High-Efficiency Thermal Management

Integrating thermal-regulating structures into energy-efficient construction materials in sustainable building design could effectively mitigate the increased global climate warming. Herein, we report a high-performance bio-based thermostat achieved through molecular engineering of hierarchically encapsulated inorganic phase-change materials (PCMs) as thermal regulators in the nanostructured lignocellulosic foam. In addition to high-compressive strength (≈20.3 MPa, more than nearly 20 times that of others), the lignocellulosic thermostat features high environmental durability under harsh conditions and also exhibits exceptional thermal-regulating ability for achieving >24.0° temperature differential as well as high fireproof performance (bearing up to 1300 °C) across a 1.0 cm thickness, serving as a dually tunable thermal thermostat during both day and night. The discards are fully biodegradable and could serve as effective fertilizer alternatives because of the incorporation of inorganic phosphorus substances. Additionally, we have verified the efficient recyclable process and demonstrated the good universality of this strategy with diverse bioresources such as wood, bamboo, rice, or corn stalks. This emerging thermostat technology offers a feasible solution for next-generation carbon-reduced building materials. It is economically viable and eco-friendly, significantly contributing to energy savings and fertilizer production through a closed-loop cycle.