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

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