Advanced layer-by-layer assembled porous rGO–Carbon architectures for efficient and stable electro-thermal energy control

Amid growing global concerns about environmental pollution and the energy crisis, cellulose-based carbon aerogels have generated significant interest as effective phase change materials for solar thermal energy storage technologies. To enhance light absorption and minimize leakage, reduced graphene oxide (rGO) can be incorporated into carbon aerogels, providing photothermal properties that quickly respond to light stimuli and thereby addressing the escalating demand for multifunctional applications. In this work, rGO films were coated on aerogel derived from waste pomelo peels (PA) using a layer-by-layer (LbL) assembly process, followed by high-temperature carbonization to create a three-dimensional, hierarchically porous carbon aerogel (CPA-rGOs). Subsequently, CPA-rGOs were vacuum-impregnated with n-octacosane as the phase change material, resulting in a high loading rate of 92.9 % and the formation of shape-stable composites (OCPA-rGOs). The OCPA-rGOs composites exhibited a low leakage rate of only 4 % by mass of n-octacosane and a high thermal storage capacity of 278.1 J/g. Additionally, CPA-rGO₁ exhibited the highest compressive strength of 448 kPa, along with excellent cyclic compression stability. Meanwhile, the OCPA-rGOs exhibit enhanced thermal and electrical conductivities, as well as thermosensitive behavior, which enables their integration into building circuits as adaptive thermal sensors. The OCPA-rGOs exhibit an exceptional solar–thermal conversion efficiency of 91.6 %. Additionally, the phase change process of the OCPA-rGO composites can be efficiently triggered by a direct current; a 10 V power supply raises the temperature to 79 °C within 8 min. Overall, these multifunctional properties make the developed OCPA-rGOs promising candidates for next-generation electro-thermal management systems in smart buildings.