Phytic Acid‐Based FeCo Bimetallic Metal‐Organic Gels for Electrocatalytic Oxygen Evolution Reaction

• Published in: Chemistry, an Asian journal an Asian journal, 2021-10, Vol.16 (20), p.3213-3220
• Main Authors: Feng, Xiying, Xiao, Yali, Huang, Hai‐Hua, Wang, Qiushi, Wu, Jinyi, Ke, Zhuofeng, Tong, Yexiang, Zhang, Jianyong
• Format: Article
• Language: English
• Subjects: Aerogels; Bimetals; Chemistry; Cobalt; electrocatalysis; Electrocatalysts; gels; hybrid materials; Iron; metal-organic gels; Morphology; Organic compounds; Oxygen evolution reactions; Phytic acid; Pyrolysis; Sol-gel processes; Transition metals; Valence
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.202100700

Electrocatalysts have been developed to improve the efficiency of gas release for oxygen evolution reaction (OER), and finding a simple and efficient method for efficient electrocatalysts has inspired research enthusiasm. Herein, we report bimetallic metal‐organic gels derived from phytic acid (PA) and mixed transition metal ions to explore their performance in electrocatalytic oxygen evolution reaction. PA is a natural phosphorus‐rich organic compound, which can be obtained from plant seeds and grains. PA reacts with bimetallic ions (Fe3+ and Co2+) in a facile one‐pot synthesis under mild conditions to form PA‐FeCo bimetallic gels, and the corresponding aerogels are further partially reduced with NaBH4 to improve the electrocatalytic activity. Mixed valence states of Fe(II)/Fe(III) and Co(III)/Co(II) are present in the materials. Excellent OER performance in terms of overpotential (257 mV at 20 mA cm−2) and Tafel slope (36 mV dec−1) is achieved in an alkaline electrolyte. This reduction method is superior to the pyrolysis method by well maintaining the gel morphology structure. This strategy is conducive to the further improvement of the performance of metal‐organic electrocatalysts, and provides guidance for the subsequent application of metal‐organic gel electrocatalysts. Bimetallic metal‐organic gels are developed in a facile one‐pot synthesis under mild conditions from mixed transition metal ions (Fe3+ and Co2+) and phytic acid (PA), a natural phosphorus resource. The corresponding aerogels are further treated with NaBH4 to show excellent performance in oxygen evolution reaction in an alkaline electrolyte. Mixed valence states of Fe and Co elements are maintained during the electrocatalytic process.