Inductive effect between atomically dispersed iridium and transition-metal hydroxide nanosheets enables highly efficient oxygen evolution reaction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2020-09, Vol.395, p.125149, Article 125149
• Main Authors: Xing, Yulin, Ku, Jiangang, Fu, Weng, Wang, Lianzhou, Chen, Huihuang
• Format: Article
• Language: English
• Subjects: Atomic Ir incorporation; Electrocatalysts; Inductive effect; Nanosheets; Oxygen evolution reaction; Transition-metal hydroxides
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.125149

•Atomic Ir-incorporated Ni(OH)2 nanosheet was fabricated via a facile precipitation method.•The inductive effect between Ni and Ir in Ir-Ni(OH)2 nanosheets promotes the generation of high-valent Ni.•The fabricated catalyst exhibits remarkable OER performance in 1 M KOH aqueous solution.•The present method is simple and universal to synthesize other highly efficient OER electrocatalysts. Oxygen evolution reaction (OER) remains the bottleneck of many energy transformation and storage technologies due to the sluggish kinetics. Transition-metal (TM) hydroxide nanosheets with high-valent TM ions possess high intrinsic catalytic activity toward OER. Herein, by taking advantage of the inductive effect, this work presents a facile and universal strategy to fabricate atomic iridium (Ir) incorporated TM hydroxide nanosheets as highly active OER electrocatalysts. As a representative, the fabricated Ir-Ni(OH)2 (4 wt% Ir) exhibits remarkable OER performance with a low overpotential (235 mV at 10 mA cm−2), a small Tafel slope (58.4 mV dec−1), and excellent durability (60 h) in alkaline solution, significantly outperforming the benchmark IrO2 and Ni(OH)2. Mechanism studies unveil that the inductive effect between Ni and Ir endows Ni(OH)2 with high-valent Ni species, which facilitate the adsorption of nucleophilic intermediates and boost the OER activity and long-term stability of Ir-Ni(OH)2. More importantly, the reported strategy could be extended to synthesize other monometallic/bimetallic TM hydroxide nanosheets (Co, CoMn) as highly efficient OER electrocatalysts. This work should pave a universal and promising avenue to rationally design and controllably synthesize efficient yet robust OER electrocatalysts in energy-related fields.