A self-supported amorphous Ni–P alloy on a CuO nanowire array: an efficient 3D electrode catalyst for water splitting in alkaline media

Abstract

Energy-efficient electrochemical water splitting is one important way to produce hydrogen fuel but still faces many challenges. In this communication, we report that an amorphous Ni-P alloy shell electrodeposited on a CuO nanowire array supported on copper foam (CuO@Ni-P NA/CF) can be used for efficient water splitting in alkaline media. As a 3D catalytic electrode, it exhibits excellent activity both for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) with overpotentials of 106 mV for HER and 275 mV for OER to achieve a current density of 30 mA cm in 1.0 M KOH. This bifunctional electrode enables a high-performance alkaline water electrolyzer to achieve a current density of 30 mA cm at a cell voltage of 1.71 V.

Nano‐Micro‐Structured Nickel‐Cobalt Hydroxide/Ni2P2O7 Assembly on Nickel Foam: An Outstanding Electrocatalyst for Alkaline Oxygen Evolution Reaction

“…The electrolysis of water in alkaline media offers a strategic pathway for producing an extensive amount of H 2 , and considered as a promising technology for addressing the environmental and techno‐economic energy problems. However, the sluggish kinetics of the anodic oxygen evolution reaction (OER) has impeded extensive application of the OER, thus fueling the search for efficient OER electrocatalysts to enhance the overall efficiency of the water‐splitting process and make the process less energy‐intensive . OER is four electron‐proton coupled reaction and can usually carried out in both acidic and alkaline media.…”

“…However, the sluggish kinetics of the anodic oxygen evolution reaction (OER) has impeded extensive application of the OER, thus fueling the search for efficient OER electrocatalysts to enhance the overall efficiency of the water-splitting process and make the process less energy-intensive. [6][7][8][9] OER is four electron-proton coupled reaction and can usually carried out in both acidic and alkaline media. Many groups studies reaction mechanism of alkaline OER, [10] however the most acceptable four elementary steps of alkaline OER mechanism are described as following [Equation (1) to (4)]:…”

In situ assembly of metal-organic framework-derived N-doped carbon/Co/CoP catalysts on carbon paper for water splitting in alkaline electrolytes

“…The development of non-noble metal HER catalysts with high activity for water splitting in alkaline media is therefore an urgent and challenging task. Significant progress has been made in recent years; molecular catalysts [14][15][16][17] and various materials (e.g., cobalt phosphide [18][19][20][21], nickel phosphide [5,22,23], iron phosphide [24], cobalt selenide [25], Pd catalyst [26][27][28][29], and CoMoS4 [30]) have been identified as electrocatalysts with excellent water splitting performances in alkaline media. These achievements prompted us to develop better catalysts.…”

A Morphologically Engineered Robust Bifunctional CuCo2O4 Nanosheet Catalyst for Highly Efficient Overall Water Splitting

“…In particular, the CuCo 2 O 4 ‐based electrocatalyst has come to attention for water splitting process due to its rich redox properties, low cost, and abundancy in nature . Figure compares the electrocatalytic HER and OER performance of our optimized CuCo 2 O 4 nanosheet (CCO nS ) with the previously reported Cu or Co‐based phosphide, sulfide, oxide, and selenide catalysts in 1.0 m KOH alkaline electrolyte solution at a current density of 10 mA cm −2 . However, the high overpotential value of these catalysts diminishes during the stability test due to inherent poor reaction kinetics, slow ion diffusion, and low electrical conductivity that deteriorate the surface faradaic reaction.…”

“…Nevertheless, overall nanosheet morphology was maintained after the HER stability test (see the inset of Figure d), revealing it robust adhesion during the long‐term stability measurement. In addition, we compared the HER overpotential (measured at 10 mA cm −2 ) of our optimized CCO nS catalyst with the state‐of‐the‐art HER catalyst being a function of the Tafel slope (Figure a,b and Figure S9d, Supporting Information), which revealed the comparatively good electrocatalytic activity.…”