Fe‐doped Nickel Carbonate Hydroxide Array Electrocatalysts for Enhanced Oxygen Evolution Reaction. Issue 27 (18th July 2022) - Tian, Zhangmin
Abstract: Developing efficient and inexpensive oxygen evolution reaction (OER) electrocatalysts is crucial to address the ever‐increasing energy crisis and environment pollution. In this work, bimetallic nickel‐iron carbonate hydroxide arrays were strongly grown on a conductive carbon cloth (NiFeCH/CC) through a facile one‐step hydrothermal method, which were used as oxygen evolution reaction (OER) electrocatalysts. Ni0.8 Fe0.2 CH/CC requires overpotential of just 246 mV at 10 mA cm −2, Tafel slope of 43 mV dec −1, and charge transfer resistance of 3.1 Ω for OER in 1 M KOH. The catalyst also shows excellent durability by a long‐term operation for 10 h. A post‐OER study of Ni0.8 Fe0.2 CH/CC reveals that the NiFeOOH species form on the surface during OER and the carbonate ions still intercalate between the cationic layers. Benefiting from a three‐dimensional structure and Fe doping strategy, the performance of Ni0.8 Fe0.2 CH/CC has been improved. This work provides an effective strategy to design efficient OER electrocatalysts in alkaline media. Abstract : A series of samples of NiFe carbonate hydroxides array were synthesized and used as OER electrocatalysts. The constructed array structure and Fe doping strategy endow Ni0.8 Fe0.2 CH/CC excellent OER performance with low overpotential of 246 mV, Tafel slope of 43 mV dec −1, and R ct of 3.1 Ω. After OER process, NiFeOOH species form on the surface and carbonate anions remain between the cationic layers.