LaMn-doped cobalt spinel catalysts for enhanced oxygen evolution performance in acidic media
Zili Zheng, Junqi Li, Taotao Zhang, Gengqin Wang, Kun Jiang, Xiaoying Hou, Cang Shi
Abstract
While cobalt-based oxides can function as OER catalysts under acidic conditions, challenges such as high overpotential and inadequate stability persist, demanding solutions to fulfill practical application demands. We utilized a rapid and efficient one-step molten salt method to synthesize LaMn-doped Co 3 O 4 supported on carbon cloth, with the aim of improving its OER activity and stability in acidic conditions. Subsequent characterization revealed that doping increased oxygen vacancies and lattice distortion within the spinel structure, while also altering the morphology of the catalyst surface, rendering it denser. In addition, the doping optimizes the electronic structure around cobalt, so that the electrons around oxygen are biased towards cobalt, which enhances the electrocatalytic activity of Co 3 O 4 and the stability of Co–O bonds. Ultimately, under 0.5 M H 2 SO 4 conditions, LaMn–Co 3 O 4 /CC exhibited superior OER activity and stability, displaying a lower overpotential of 370 mV at a current density of 10 mA cm −2 and maintaining stability for over 24 h, a notable enhancement compared to pure Co 3 O 4 .