Chemically tailored biomass sponge-based hierarchical porous carbon for superior solar thermal energy harvesting and stable thermal energy storage/release

In the past work, almost all biomass sponge-based hierarchical porous carbons are tried to preserve the original 3D porous structure as much as possible, thus restricting their effectiveness in thermal energy utilization. In current work, loofah sponge-based hierarchical porous carbon covering nanometer to micrometer was fabricated through a crosslinking-carbonization-etching chemically tailored process. The re-constructed hierarchical porous carbons (LHPCs) have totally different characteristics from that depending on original 3D pores. The LHPC-based composite phase change materials (PCMs) exhibited the maximum melting/solidifying latent heat of 155.1/158.7 J g−1 and exceptional thermal reliability. The optimal solar-thermal converting efficiency of the composite PCMs topped 95 %, higher than some expensive carbon-based materials. Compared to previously reported work, the fabricated composite PCMs showed improved thermal energy storage/release capability and solar-heat conversion efficiency. Additionally, the regulation of about 6.3 °C for composite PCMs was achieved in a hut test. This work has further advanced a superior porous carbon-tailored strategy compared to the traditional approach, building upon the original 3D porous structure.