FeNi2P three-dimensional oriented nanosheet array bifunctional catalysts with better full water splitting performance than the full noble metal catalysts

Songmin Lin; Yuan Yu; Dongfeng Sun; Fangyou Meng; Wenhui Chu; Linyin Huang; Jie Ren; Qingmei Su; Shufang Ma; Bingshe Xu

doi:10.1016/j.jcis.2021.09.166

FeNi₂P three-dimensional oriented nanosheet array bifunctional catalysts with better full water splitting performance than the full noble metal catalysts

J Colloid Interface Sci. 2022 Feb 15;608(Pt 3):2192-2202. doi: 10.1016/j.jcis.2021.09.166. Epub 2021 Sep 28.

Authors

Songmin Lin¹, Yuan Yu², Dongfeng Sun³, Fangyou Meng¹, Wenhui Chu¹, Linyin Huang¹, Jie Ren¹, Qingmei Su⁴, Shufang Ma⁴, Bingshe Xu⁴

Affiliations

¹ Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi'an 710021, China; School of Materials Science & Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
² Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi'an 710021, China. Electronic address: yuyuan@sust.edu.cn.
³ Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi'an 710021, China. Electronic address: sundongfeng@sust.edu.cn.
⁴ Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi'an 710021, China.

PMID: 34785047
DOI: 10.1016/j.jcis.2021.09.166

Abstract

The 3D (three-dimensional) oriented nanosheet array FeNi₂P electrocatalyst grown on carbon cloth (FeNi₂P/CC) is explored in this work. This unique 3D oriented nanosheet array structure can expose more catalytic active sites, promote the penetration of electrolyte solution on the catalyst surface, and facilitate the transfer of ions, thus speeding up the kinetic process of Hydrogen evolution reaction (HER) and Oxygen evolution reaction (OER). At the current densities of 10 mA/cm² in 1 M KOH solution, the HER overpotential (71 mV) of the FeNi₂P/CC self-supporting electrode is very close to that of noble metal HER catalyst of 20% Pt/C (54 mV), and its OER overpotential (210 mV) is 34% lower than that of the precious metal OER catalyst of RuO₂ (318 mV), demonstrating the excellent electrocatalytic performance of the FeNi₂P/CC catalyst. Moreover, the cell voltage for full water splitting (at 10 mA/cm² current densities) of the FeNi₂P/CC bifunctional electrode cell is 1.52 V, which is 3.8% lower than that of the full noble-metal electrode reference cell (RuO₂ || Pt/C, 1.58 V), suggesting that this FeNi₂P/CC bifunctional catalyst is likely to replace precious metals to reduce the costs in full water splitting application. According to density functional theory (DFT) calculation results, the introduction of iron atom can change the electronic structure of the Ni₂P, so it can reduce the adsorption energy of hydrogen and oxygen, and facilitate the adsorption and desorption of hydrogen and oxygen on the surface of the catalyst, improving its performance of HER and OER.

Keywords: Alkaline medium; Electrocatalysts; Full water splitting; Nanosheet.