Porous bimetallic cobalt-iron phosphide nanofoam for efficient and stable oxygen evolution catalysis

Shanfu Sun; Ming Zheng; Pengfei Cheng; Fugui Wu; Luping Xu

doi:10.1016/j.jcis.2022.06.053

Porous bimetallic cobalt-iron phosphide nanofoam for efficient and stable oxygen evolution catalysis

J Colloid Interface Sci. 2022 Nov 15:626:515-523. doi: 10.1016/j.jcis.2022.06.053. Epub 2022 Jun 16.

Authors

Shanfu Sun¹, Ming Zheng², Pengfei Cheng³, Fugui Wu², Luping Xu⁴

Affiliations

¹ School of Aerospace Science and Technology, Xidian University, Xi'an 710126, PR China.
² School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China.
³ School of Aerospace Science and Technology, Xidian University, Xi'an 710126, PR China. Electronic address: pfcheng@xidian.edu.cn.
⁴ School of Aerospace Science and Technology, Xidian University, Xi'an 710126, PR China. Electronic address: lpxu@mail.xidian.edu.cn.

PMID: 35809440
DOI: 10.1016/j.jcis.2022.06.053

Abstract

Developing oxygen evolution reaction (OER) catalysts with high activity and long-term stability is critical to achieving efficient hydrogen production from water electrolysis. Herein, a porous bimetallic cobalt-iron phosphide (CoFe-P) nanofoam is synthesized via a novel one-pot glucose-blowing followed by oxidization and then phosphidization process. The CoFe-P nanofoam presents a porous nanostructure which contributes to contact with electrolytes and release of generated gas during electrocatalytic reactions. As OER catalysts in alkaline, the bimetallic porous CoFe-P nanofoam exhibit a lower overpotential (258 mV@10 mA cm^-2) as well as outstanding stability (70 h@100 mA cm^-2), which surpasses the RuO₂ and is comparable to many high-performance Co and Fe-based catalysts. It is demonstrated that the surface of CoFe-P undergo a reconstruction process and form new high active (Co_xFe_1-x)OOH. Density functional theory (DFT) calculations reveal that the elevated activity is caused by the bimetal Co and Fe optimizing the d-band center (E_d) energy levels and thus balancing the adsorption-desorption capacities for OER intermediates. This work through constructing porous bimetallic nanofoam offers a feasible strategy to facilitate the reaction activity and prolong the long-term stability of OER.

Keywords: CoFe-P; Oxygen evolution reaction; Oxyhydroxides; Porous nanofoam; Stability.