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

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/cm(2) 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/cm(2) 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 parallel to 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. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study explores the performance of a 3D oriented nanosheet array FeNi2P electrocatalyst grown on carbon cloth. This unique structure provides more catalytic active sites, promotes electrolyte penetration, and facilitates ion transfer, resulting in excellent electrocatalytic performance for hydrogen and oxygen reactions.