Construction of a Pliable Electrode System for Effective Electrochemical Oxygen Evolution Reaction: Direct Growth of Nickel/Iron/Selenide Nanohybrids on Nickel Foil

Abstract

Numerous attempts have been made to prepare electrocatalytic nanomaterials and construct electrode systems for effective water-splitting reactions. The growth of transition metal-based heterostructures directly on specific substrates is promising for electrocatalytic applications. In the current work, nickel/iron hydroxide nanohybrids and nickel/iron/selenide nanohybrids are successfully synthesized on selected substrates such as graphite and nickel foil in solution. In particular, nickel/iron/selenide nanohybrids on nickel foil (NF-[NiFeSe]) exhibit substantially enhanced OER catalytic activity with low overpotential and Tafel slope values, as well as high durability. The use of pliable nickel foil with the direct growth of heterostructured nickel/iron/selenide nanohybrids can be employed to effectively and economically design high-performance water-splitting devices.

Effects of Electrochemical Conditioning on Nickel-Based Oxygen Evolution Electrocatalysts

“…In this regard, a controlled study that performs electrochemical conditioning of OER electrocatalysts with the same material properties is necessary to identify the effects of CP (or CA) and CV electrochemical conditioning on the electrochemical activation processes and OER activity. In addition, Ni-based substrates, such as Ni foam and Ni foil, have been widely used as substrates for OER electrocatalysts due to their high electrical conductivity and robustness. − However, considering that electrochemically activated OER electrocatalysts have electrolyte-permeable structures and Ni is an OER active material, , there is a possibility that Ni-based substrates may also be exposed to the electrolyte, undergo in situ oxidation during electrochemical conditioning, and be involved in the OER, which requires further investigation.…”

Effects of Electrochemical Conditioning on Nickel-based Oxygen Evolution Electrocatalysts

“…Given Ni is one of the most commonly used OER active transition metals in the alkaline electrolyte and substrates material (e.g., Ni foam and Ni foil) for OER electrocatalysts, [28][29][30][31][32] Ni foil is a suitable choice for the study of the fundamental characteristics of CP and CV electrochemical conditioning methods for alkaline OER electrocatalysts. Although electrochemical behaviors of Ni in alkaline media have been widely studied, [34][35][36][37] it needs further investigation focused on material properties and OER characteristics of Ni after CP and CV electrochemical conditioning in both Fe-purified and Fe-unpurified alkaline electrolytes.…”

“…Ni-based substrates (e.g., Ni foam and Ni foil) have been widely employed as substrates for OER precatalysts. [28][29][30][31][32] So far, when measuring and interpreting the OER performance, the contribution of Ni-based substrates to OER electrocatalysis has rarely been considered. However, considering that in situ oxidation can occur throughout the entire OER precatalyst layer during electrochemical conditioning as discussed in Section 2.…”

“…In addition, Ni-based substrates, such as Ni foam and Ni foil, have been widely used as substrates for OER electrocatalysts due to their high electrical conductivity and robustness. [28][29][30][31][32] However, considering electrochemically activated OER electrocatalysts have electrolyte-permeable structures and Ni is an OER active material, 11,33 there is a possibility that Ni-based substrates may also be exposed to the electrolyte, undergo in situ oxidation during electrochemical conditioning, and be involved in the OER, which requires further investigation. S1.…”

Direct growth and post-treatment of zeolitic imidazolate framework-67 on carbon paper: an effective and stable electrode system for electrocatalytic reactions

“…To prevent the current limitations, direct growth of catalytically active materials on a conductive substrate could be an improved fabrication strategy for realizing durable electrode systems. [12][13][14][15][16] This approach can enhance the interaction between a catalyst and its substrate, thereby signicantly promoting the electron transfer and durability of the former. 15,[17][18][19][20][21] Metal-organic frameworks (MOFs) have emerged as advanced materials with high surface areas, uniform crystallinities, and high porosities.…”