Nickel-Based Electrocatalysts for Water Electrolysis

Abstract

Currently, hydrogen production is based on the reforming process, leading to the emission of pollutants; therefore, a substitute production method is imminently required. Water electrolysis is an ideal alternative for large-scale hydrogen production, as it does not produce any carbon-based pollutant byproducts. The production of green hydrogen from water electrolysis using intermittent sources (e.g., solar and eolic sources) would facilitate clean energy storage. However, the electrocatalysts currently required for water electrolysis are noble metals, making this potential option expensive and inaccessible for industrial applications. Therefore, there is a need to develop electrocatalysts based on earth-abundant and low-cost metals. Nickel-based electrocatalysts are a fitting alternative because they are economically accessible. Extensive research has focused on developing nickel-based electrocatalysts for hydrogen and oxygen evolution. Theoretical and experimental work have addressed the elucidation of these electrochemical processes and the role of heteroatoms, structure, and morphology. Even though some works tend to be contradictory, they have lit up the path for the development of efficient nickel-based electrocatalysts. For these reasons, a review of recent progress is presented herein.

An efficient and stable iodine-doped nickel hydroxide electrocatalyst for water oxidation: synthesis, electrochemical performance, and stability

“…24 Various strategies have been adopted to improve the electrocatalytic activity of materials based on earth-abundant nickel, including doping with metallic or non-metallic ions, creating binary or ternary composites, forming a hybrid with other conducting materials. 25,26 The addition of foreign nonmetal heteroatoms or their anions to improve the OER activity of Ni-based catalysts can have a considerable effect. The doping with halogens is another important strategy to boost the electrocatalytic performance of materials.…”

Synthesis of MFe2O4 (M=Ni, Co) Nanoparticles by a Bicontinuous Microemulsion Method for the Oxygen Evolution Reaction

“…(4)). The smaller Tafel slope of the CoFe 2 O 4 NPs in the particular range of current density shows a small overpotential loss; hence, a larger current density can be achieved with a relatively low overpotential ($${\eta )}$$ [45,46] …”

“…The smaller Tafel slope of the CoFe 2 O 4 NPs in the particular range of current density shows a small overpotential loss; hence, a larger current density can be achieved with a relatively low overpotential ( hÞ. [45,46] Catalysts with smaller Tafel slopes and minimum overpotential are considered the best electrocatalysts for OER. As shown in Figure 7(c), variations in the electrochemical activity of both samples can be summarized, representing overpotential vs. Tafel slope.…”

Phytochemical-assisted green synthesis of CuFeOx nano-rose electrocatalysts for oxygen evolution reaction in alkaline media

“…24,25 Generally, the use of organic molecules as capping and complexing agents are commonly employed strategies to achieve interesting morphologies of electrocatalysts directly grown on conductive substrates. [26][27][28] The decoration of foreign materials in such nanostructures play a vital role in the OER catalysis process. 29 Introducing inexpensive and easily accessible transitional metals (TMs) into a multiphase system is considered more benecial for creating more active points that enhance electrical conductivity and ultimately lead to improved performance.…”