ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of the valence state of initial iron source on oxygen evolution activity of Fe-doped Ni-MOF

Dandan Zhang, Renxing Huang, Huaming Xie, Ruizhen Li, Xingyong Liu, Ming Pan, and Ying Lei

College of Chemical Engineering, Sichuan University of Science and Engineering, Zigong, People’s Republic of China

E-mail: lynnely1209@suse.edu.cn

Received: 21 November 2019  Accepted: 18 February 2020

Abstract:

Abstract

The coordination structure of MOF is strongly influenced by central metal ions. Here, we designed and prepared iron-doped nickel metal–organic framework (Fe-doped Ni-MOF) by employing different initial iron sources (Fe²⁺, Fe³⁺). Specifically, Fe-doped Ni-MOF with divalent iron ions as initial iron sources exhibits superior performance with respect to trivalent iron ions, showing excellent electrocatalytic performance toward OER with an overpotential (294 mV at 10 mA cm⁻²), low Tafel slope (47.45 mV dec⁻¹) and large electrochemically active surface area in alkaline electrolytes. Furthermore, there is no obvious decay after long-term operation up to 25 h. To inspect the origin of OER activity enhancement, we resorted to XRD, SEM, TEM, XPS and N₂ adsorption–desorption techniques and various electrochemical methods to analyze them in detail. These studies provide a new vision into understanding Fe-doped Ni-MOF for OER, shedding light on designing novel and highly efficient MOF materials for electrocatalysis.

Graphic abstract

Keywords: Oxygen evolution reaction; Fe doped; Metal–organic framework; Divalent iron

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01112-6

Chemical Papers 74 (9) 2775–2784 (2020)