Emerging surface strategies for porous materials-based phase change composites

Porous materials have been widely used to encapsulate phase change materials (PCMs) and enhance their thermal performances. However, the original porous materials possess monotonic properties and cannot endow PCMs with multiple functions, thus limiting their applications. Therefore, various surface strategies have been explored to modify the porous materials to extend the application scenarios of PCMs. Herein, we comprehensively review the surface-modified porous materials based on various modifiers, such as carbon-based materials, metallic/metallic oxide materials, MXenes, metal-organic frameworks, elements, and molecules. Those modifiers form a thin adlayer on the porous substrate and endow it with multiple features, such as high thermal/electrical conductivity, large loading capacity of PCMs, hydrophilicity/hydrophobicity, full-spectrum light adsorption, and flame retardant. The preparation and modification methods for surface-modified porous materials are elaborated upon in this paper. Finally, we summarize the significant current achievements, future challenges, and opportunities for the gradual development of novelties in thermal energy storage.