Magnetically accelerated thermal energy storage within Fe3O4‐anchored MXene‐based phase change materials

Abstract Inherent weak photon‐capturing ability is a long‐standing bottleneck for pristine phase change materials (PCMs) in photothermal conversion application. To conquer this difficulty, herein, magnetic Fe 3 O 4 nanoparticles were in situ anchored between the layers and the surface of two‐dimensional MXene for the infiltration of myristic acid (MA) by an in situ chemical anchoring strategy. Benefiting from the synergistic localized surface plasmon resonance effect of MXene and Fe 3 O 4 nanoparticles, our designed MXene@Fe 3 O 4 ‐MA composite PCMs harvested an ultrahigh photothermal conversion efficiency of 97.7%. During the photothermal conversion process, MXene can capture photons and convert solar energy into heat energy efficiently, and the in situ anchored Fe 3 O 4 nanoparticles further enhanced the photothermal conversion efficiency. Moreover, the introduction of Fe 3 O 4 nanoparticles improved the thermal energy storage density (144.17 J/g) of MXene‐MA composite PCMs since Fe 3 O 4 nanoparticles provided more heterogeneous nucleation sites for MA. Simultaneously, MXene@Fe 3 O 4 ‐MA composite PCMs were endowed with excellent paramagnetism, and realized efficient magnetic‐thermal conversion. Additionally, MXene@Fe 3 O 4 ‐MA composite PCMs exhibited excellent energy conversion stability, thermal stability, and reliability after undergoing multiple thermal cycles. Therefore, high‐performance MXene@Fe 3 O 4 ‐based energy conversion composite PCMs are promising candidates to accelerate efficient utilization of the practical solar energy and magnetic energy