Strain engineering induced surfacial catalytic amorphous Ni3C with room temperature ferromagnetism for magnetic heating enhancement of overall water-splitting

[Display omitted] •Surfacial amorphization of confined nanoparticles is realized by strain engineering.•Surfacial amorphized nanoparticles exhibit high overall water-splitting activity.•Nanoparticles with amorphous Ni3C shell exhibit room temperature ferromagnetism.•Under alternating magnetic fields, water-splitting performance is greatly improved. Amorphous materials have been recognized as highly active electrocatalysts due to their abundant active sites stems from unsaturated chemical bonds. In addition, the application of alternating magnetic fields (AMF) to achieve magnetic heating effect has gradually become an important means to improve the performance of magnetic catalysts. Here, we have successfully realized the surfacial amorphization of confined Ni3C nanoparticles by using interfacial strain engineering. As expected, the surfacial amorphized Ni3C nanoparticles exhibit remarkable properties in electrochemical water-splitting. More importantly, magnetic measurements show that the surfacial amorphized Ni3C nanoparticles have room temperature ferromagnetism, which is consistent with our theoretical calculation results. Accordingly, under AMF stimulation, its overall water-splitting performance is further greatly improved as the result of magnetic heating effect associated with Néel relaxation. This work provides a new strategy for the development of highly efficient surfacial amorphized catalysts, and promotes the application of magnetothermal technology in amorphous catalysis.