Adjusting electronic structure coupling of Fe–Ni2P (NiFeP-MOF) multilevel structure for ultra-activity and durable catalytic water oxidation

• Published in: International journal of hydrogen energy 2022-08, Vol.47 (71), p.30472-30483
• Main Authors: Qiu, Shipeng, Hao, Shuhua, Xing, Yupeng, Huang, Jinzhao, Wang, Xiao, Ding, Meng, Zhao, Gang, Zhang, Baojie, Zhang, Yafang
• Format: Article
• Language: English
• Subjects: Fe–Ni2P electrocatalyst; Multilevel structure; Ni-MOF; Oxygen evolution reaction; Phosphorus-engineered
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.07.013

Efficient electrocatalyst for alkaline oxygen evolution reaction is the critical core to the wide application of metal-air energy storage and water electrolysis hydrogen energy. Therefore, appropriate design of highly active and stable non-noble metal oxygen evolution electrocatalyst with good electronic structure and multilevel structure is both a goal and a challenge. Here, we report a Fe–Ni2P electrocatalyst (NiFeP-MOF) with multilevel structure, which was obtained by anion exchange on the basis of Fe–Ni(OH)2 (NiFe-MOF) grown on nickel foam in situ by solvothermal method. As expected, Fe substitution regulates the Ni oxidation state in the NiFeP-MOF and realizes electronic structure coupling, showing a highly active and stable oxygen evolution reaction (OER) in alkaline electrolyte solution. Specifically, the NiFeP-MOF demonstrates an ultralow overpotentials (232 mV, 10 mA cm−2; 267 mV 100 mA cm−2), respectively, an extremely small Tafel slope (34 mV dec−1). Separately, the electrocatalyst shows an excellent cycle stability at 10 mA cm−2 for 12 h (43,200 s). More importantly, this work come up with an available policy for the preparation of excellent alkaline hydrolysis electrolysis catalysts and air cathodes with excellent performance. •Fe–Ni2P (NiFeP-MOF) electrocatalyst with multilevel structure is obtained.•The synthesized catalysts have excellent OER performance and catalytic stability.•The catalyst with Ni:Fe ratio of 2:1 has high activity and good stability.•Fe substitution regulates the Ni oxidation state realizes electronic structure coupling.