Boosting activity on molten salt-synthesized Ce doped cobalt hydroxyl nitrate nanorods by oxygen vacancies for efficient oxygen evolution

Rationalizing the development of highly active, non-precious electrocatalysts through facile and cost-effective synthesis methods for the oxygen evolution reaction (OER) constitutes a paramount research objective. In this study, we introduce an innovative molten salt approach to fabricate an arrayed nanorod architecture supported on a cobalt foam substrate denoted as Ce doped cobalt hydroxyl nitrate (Ce-CoNH). Cerium (Ce) is strategically employed to induce oxygen vacancies and effect localized electronic structure modifications of the cobalt (Co) sites. In comparison to individual CoNH catalysts, Ce-CoNH exhibits exceptional catalytic activity in alkaline water oxidation, achieving a notably low overpotential of 270 mV at a current density of 50 mA cm−2. Notably, the Ce-CoNH catalyst also demonstrates remarkable durability, sustaining a current density of 100 mA cm−2 for an impressive duration of 50 h, surpassing the performance of Ce-free CoNH samples, which can be attributed to the flexible influence of Ce doping and the robust nanorod structure. Collectively, our study underscores the viability of molten salt-synthesized heteroatom substitution, accompanied by the introduction of defect-rich structures, as an effective strategy for the rational design of advanced electrocatalysts tailored for water electrolysis applications.