Discharge‐Induced Enhancement of the Oxygen Evolution Reaction.

Hao, Jinhui; Luo, Wei; Wang, Shuaishuai; Zhao, Kun; Hou, Jianwen; Li, Longhua; Ge, Baoxin; Yang, Wenshu; Shi, Weidong

The fundamental understanding of the surface reconstruction induced by the applied potential is of great significance for enhancing the oxygen evolution reaction (OER). Here, we show that a previously overlooked discharge current in the low applied potential region also leads to in situ electrochemical activation of a nitrogen‐doped nickel oxyhydroxide surface. We exploit the fact that doping of heteroatoms weakens the surface structure, and hence, a weak discharge current originating from the capacitive nature of nickel oxyhydroxide has a strong structure‐reforming ability to promote the formation of nitrogen and oxygen vacancies. The current density at 1.4 V (vs. Hg/HgO) can dramatically increase by as much as 31.3 % after discharge in the low applied potential region. This work provides insight into in situ enhancement of the OER and suggests that the low applied potential region must be a primary consideration in evaluating the origin of the activity of electrocatalysts.

OXYGEN evolution reactions; SURFACE reconstruction; STEAM reforming; SURFACE structure; NITROGEN

Angewandte Chemie, 2021, Vol 133, Issue 36, p20195

0044-8249

Academic Journal

10.1002/ange.202108770