Magnetic-Field-Induced Strain Enhances Electrocatalysis of FeCo Alloys on Anode Catalysts for Water Splitting

Abstract

In water splitting, the oxygen evolution reaction (OER) performance of transition metal alloy catalysts needs to be further improved. To solve this problem, the method of an external magnetic field was used to improve the OER catalytic performance of the alloy catalyst. In this paper, FeCo alloys with different composition ratios were prepared by an arc melting method, and OER catalysts with different compositions were obtained by annealing treatment. Under the action of a magnetic field, all three groups of catalysts showed a better catalytic performance than those without a magnetic field. The overpotentials of Fe35Co65, Fe22Co78 and Fe15Co85 at a current density of 20 mA cm−2 were reduced by 12 mV, 6 mV and 2 mV, respectively. It is found that, due to the magnetostrictive properties of FeCo alloys, the catalyst itself will generate strain under the action of a magnetic field, and the existence of strain may be the main reason for the enhanced OER performance of the magnetic field. Therefore, this work provides a new idea for the development of magnetic material catalysts and a magnetic field to improve the performance of catalysts.