Hyperbranched NixPy/NiCoP Arrays Based on Nickel Foam Electrode for Efficient and Stable Electrocatalytic Hydrogen Evolution

Abstract

Transition metal phosphides have high catalytic performance and stability among non-precious metal electrocatalysts, particularly exhibiting good hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in alkaline solutions, due to the platinum-like electronic structure of transition metal phosphides. In this study, we successfully synthesized nickel phosphide and nickel cobalt phosphate hybrid on the three-dimensional nickel foam by a facile hydrothermal method. It is worth noting that the NixPy/NiCoP in 1 M KOH only needs the overpotential of 95 mV to reach the current density of 10 mA∙cm⁻² for hydrogen evolution reaction (HER) and the overpotential of 231 mV at 10 mA∙cm⁻² for oxygen evolution reaction (OER), which is superior to most electrocatalysts. The obtained results indicate that there is a synergistic effect between the three elements of Ni, Co, and P, facilitating the process of electrocatalysis. Meanwhile, the synthesized electrode not only has a large active surface area, but also good electrical conductivity, effectively facilitating the electrocatalytic reaction kinetics. Thus, this work provides an effective route to a low-cost, high-performance catalyst for electrocatalytic hydrogen production.

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https://doi.org/10.1007/s12678-022-00747-1
ORIGINAL RESEARCH
Hyperbranched NixPy/NiCoP Arrays Based onNickel Foam Electrode
forEfficient andStable Electrocatalytic Hydrogen Evolution
ZhixinLiu1· ZhengangGuo1,2 · FasongYang1· ZhifengLiu1,2
Accepted: 16 May 2022
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2022
Abstract
Transition metal phosphides have high catalytic performance and stability among non-precious metal electrocatalysts,
particularly exhibiting good hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in
alkaline solutions, due to the platinum-like electronic structure of transition metal phosphides. In this study, we success-
fully synthesized nickel phosphide and nickel cobalt phosphate hybrid on the three-dimensional nickel foam by a facile
hydrothermal method. It is worth noting that the NixPy/NiCoP in 1M KOH only needs the overpotential of 95mV to reach
the current density of 10mA∙cm−2 for hydrogen evolution reaction (HER) and the overpotential of 231mV at 10mA∙cm−2
for oxygen evolution reaction (OER), which is superior to most electrocatalysts. The obtained results indicate that there is
a synergistic effect between the three elements of Ni, Co, and P, facilitating the process of electrocatalysis. Meanwhile, the
synthesized electrode not only has a large active surface area, but also good electrical conductivity, effectively facilitating
the electrocatalytic reaction kinetics. Thus, this work provides an effective route to a low-cost, high-performance catalyst
for electrocatalytic hydrogen production.
Keywords Phosphides· Nanostructure· Electrocatalysis· Activity· Hydrogen–oxygen reaction
Introduction
Along with the rapid consumption of traditional fossil
energy and increasing environment problems, we need to
explore sustainable clean energy to substitute for fossil
energy, in which hydrogen is one of the most potential clean
and renewable energy sources [1–4]. Due to its abundance,
high energy density, and environmentally friendly proper-
ties, hydrogen (H2) has become a potential alternative for
future energy production in fuel cell systems and portable
devices [5–7]. The ideal method of continuous hydrogen
supply is to use the electric energy to drive the water decom-
position reaction, which also has the potential to produce
hydrogen on a commercial scale [8, 9]. Water splitting
involves two half reactions, i.e., hydrogen evolution reaction
(HER) and oxygen evolution reaction (OER). The rate of
oxygen evolution reaction in the process of water electrolysis
is slow, due to the slow kinetics of the four-electron oxida-
tion of water molecules and the formation of relatively weak
oxygen–oxygen bonds (4OH− → O2 + 2H2O). However, the
hydrogen evolution reaction has only two-electron transfer
(2H++ 2e− → H2), which is much faster. Both HER and
OER require electrocatalysts to obtain a good reaction rate
and improve the efficiency. So far, the precious metal Pt and
RuO2 or IrO2 are considered to be the best electrocatalysts
for HER and OER. Nevertheless, their high cost and scar-
city of resources limit this kind of catalyst wide application.
Much work has been done on the design and synthesis of
highly efficient catalysts for HER and OER, focusing on the
search for new cost-effective and resource-rich electrocata-
lysts as alternative to noble metal catalysts (Pt, RuO2, and
IrO2) [10–14].
Up to now, researchers have discovered plenty of elec-
trocatalysts based on earth-abundant transition metal
compounds, for instance, transition-metal oxides [15, 16],
carbides [17, 18], sulfides [14, 16, 19–21], nitrides [22,
23], borides [20, 24], and phosphides [25–28], among
which transition metal phosphides (TMPs) have attached
much attention due to their exhibit intrinsically electrical
* Zhengang Guo
zhengangguo@126.com
1 School ofMaterials Science andEngineering, Tianjin
Chengjian University, Tianjin300384, China
2 Tianjin Key Laboratory ofBuilding Green Functional
Materials, Tianjin300384, China
Electrocatalysis (2022) 13:611–621
/ Publishedonline: 28 May 2022
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