Photoelectromagnetic multimode triggered phase change materials for thermotherapy

Abstract Neither pristine phase change materials (PCMs) nor metal‐organic frameworks (MOFs) can be driven by optical/electrical/magnetic triggers for multiple energy conversion and thermal storage, which cannot satisfy the requirements of multi‐scenario applications. Herein, a three‐dimensional interconnected forest‐type array carbon network anchored by Co nanoparticles serving as optical/electrical/magnetic multimode triggers was developed through in situ growth of two‐dimensional MOF nanosheet arrays on pre‐carbonized melamine foam and subsequent high‐temperature carbonization. After the encapsulation of polyethylene glycol, the resulting composite PCMs simultaneously integrate fascinating photothermal, electrothermal, magnetothermal conversion and storage for personal thermotherapy. Benefiting from the synergistic enhancement of forest‐type array carbon heterostructure and Co nanoparticles, composite PCMs exhibit high thermal/electrical conduction and strong full‐spectrum absorption capacities. Resultantly, low‐energy photoelectric triggers are sufficient to drive high‐efficiency photothermal/electrothermal conversion and storage of composite PCMs (93.1%, 100 mW/cm²; 92.9%, 2.5 V). Additionally, composite PCMs also exhibit excellent encapsulation stability without liquid phase leakage, long‐term thermal reliability and multiple energy conversion and storage stability after multiple cycles. The proposed photoelectromagnetic multimode triggers are aimed to inspire innovation and accelerate major breakthroughs in advanced responsive composite PCMs toward multiple energy utilization and personal thermotherapy.