Magnetic Enhancement of Oxygen Evolution in CoNi@C Nanosheets
Li Han, Shucheng Liu, Yi Liu
Abstract
Recently, electron spin manipulation is being considered as a potential technique to promote oxygen electrocatalytic reactions; however, the specific spin-polarized kinetics remain unclear. In this work, a series of magnetic electrocatalysts, CoNi@C, was successfully prepared. The catalysts exhibited room-temperature ferromagnetism with a high saturation magnetization (over 50 emu/g). An external magnetic field significantly improved the catalytic activity for the oxygen evolution of the catalysts under alkaline conditions. The oxygen evolution reaction overpotential of the catalysts decreased by 14 mV, and the Tafel slope decreased by 22.41 mV·dec–1 when a permanent magnetic field (∼360 mT) was applied. This magnetic enhancement effect arises from the promotion of electron transfer and oxygen adsorption due to spin polarization and alignment. This study demonstrates a promising strategy of using magnetic induction to boost oxygen evolution activity of magnetic electrocatalysts.