Magnetic Heating Enhancement For Oxygen Evolution Reaction On Confined CoSe₂ Nanoparticles

Transition metal chalcogenides（TMDs）are a new type of electrocatalysts with high electron transfer efficiently in electrochemical reactions.Researchers can manipulate TMDs electronic structure and surface chemical properties through synthesis methods and structural design to optimize their electrocatalytic performance.Nowadays,it has been a bottleneck to improve the electrocatalytic activity and stability of TMDs by changing the coordination environment,crystal structure and oxidation state of their surface.However,nano-confined catalysis and magnetic-assisted electrocatalysis are effective strategies that are expected to break through this bottleneck.In this paper,a strategy of combining nano-confined catalysis with magnetic field-assisted electrocatalysis is proposed,and a scheme is designed to improve the performance of oxygen evolution reaction by the Néel relaxation of the superparamagnetic Co Se₂ nanoparticles in the high frequency alternating magnetic field（AMF）to produce effective local heating.（1）CoSe₂ nanoparticles confined in amorphous carbon were prepared insitu on glassy carbon sheet by pulsed laser deposition and rapid thermal annealing treatment.According to TEM,SEM,Raman,XRD and XPS characterization results,the size of CoSe₂ nanoparticles is about 3.5nm with high crystallinity.VSM results prove that Co Se₂ nanoparticles have room temperature superparamagnetism,which provides a platform for the subsequent introduction of AMF assisted electrocatalysis.（2）The glassy carbon sheet loaded with confined CoSe₂ nanoparticles was used as the working electrode of OER,and high-frequency AMF was introduced to assist the electrocatalytic reaction.It was found that high-frequency AMF significantly improved the OER performance.Due to the rapid reversal of magnetic moment of Co Se₂nanoparticles under high frequency AMF,resulting in local heating of electrocatalyst.This proves that the use of high-frequency AMF to locally heat Co Se₂ nanoparticles can enhance the OER kinetics.The surface temperature of the electrode was only increased by a few degrees Celsius through the infrared thermometer,but the improvement in performance was equivalent to the increase in particle temperature to about 200℃.This local heating method can not only speed up the reaction speed through temperature effect,but also avoid heating of the whole electrolytic cell,and extend the service life of the electrolytic cell.Our work has inspired how to design AMF-assisted electrocatalysis and inject new inspiration into the field of electrocatalysis.