Metal–Organic Framework-Based Self-Supporting Nanoparticle Arrays for Catalytic Water Splitting

Abstract

One of the efficient methods for achieving the carbon peaking and carbon neutrality goals is the generation of hydrogen from water splitting. It has been proven that reasonable nanoengineering is an important strategy to increase the performance of non-noble-metal catalysts. A metal−organic framework (MOF) is a kind of porous and versatile nanomaterial that has great potential for industrial application in water electrolysis technology. However, MOF materials are mostly powders, which greatly limits their ability to be used directly as electrode materials in practical applications. Therefore, this paper innovatively designs a general strategy to prepare controlled MOF-based three-dimensional nanoparticle-array-structured catalysts with self-support and well-orientation on the surface of nickel foam. This strategy consists of simple hydrothermal, stable stirring, and high-temperature calcination methods. In this work, the self-supporting nanoparticle-array catalyst (ZIF-67/NiCo-S/NF) is successfully prepared using 2-methylimidazole cobalt salt (ZIF-67). The special structure and composition of ZIF-67/NiCo-S/NF provide several beneficial features such as a synergistic effect, high specific surface area, fast electron transport, more exposed active sites, and enhanced electrochemical stability. At room temperature and in a 1 M KOH solution, ZIF-67/NiCo-S/NF only needs 147 and 127 mV overpotentials to obtain a current density of 10 mA cm −2 for hydrogen and oxygen evolution reactions, respectively. The excellent performance of ZIF-67/NiCo-S/NF makes it a potential industrial water-splitting catalyst for hydrogen production. This study presents a general strategy for the synthesis of self-supporting nanoparticle arrays based on the MOF, which offers a new line for the preparation of more nanoscale electrocatalysts.

Water Splitting as an Alternative for Electrochemical Hydrogen and Oxygen Generation: Current Status, Trends, and Challenges

“…An approach to face the low efficiencies is the oxidation of organic molecules such as methanol, ethanol, urea, etc., which are more thermodynamically favorable [76]. In this sense, etha- Another relevant work was developed by Shen et al in which controlled tridimensional ZIF-67/NiCo-S/NF was prepared by a feasible strategy consisting of a simple hydrothermal process, stable stirring, and high-temperature treatment [74]. As the other reported electroactive MOF, this material shows an excellent synergetic effect, high surface area, good electron transfer, and excellent stability.…”

Free-Standing Dendritic Nanostructured Co/CNT/Carbon Nanofiber Composites for Efficient Water Splitting in Alkaline Media

“…Hydrogen energy, as a renewable, high-energy-density, and earth-abundant energy resource, is considered as an ideal substitute for traditional fossil fuel. Currently, water splitting is evoking intensive investigations to largely generate the clean hydrogen fuel. − It involves the H 2 evolution reaction (HER) and O 2 evolution reaction (OER) with high overpotential. Catalyst applications could decrease necessary overpotential (η) for actuating the conversion efficiency.…”

Constructing Molybdenum Phosphide@Cobalt Phosphide Heterostructure Nanoarrays on Nickel Foam as a Bifunctional Electrocatalyst for Enhanced Overall Water Splitting

“…The maximum utilization of a heterogeneous interface can provide full play to the overall performance of the catalyst. Hence, by virtue of the characteristics of small particle size and large specific surface area, small-sized nanoparticles have more active sites, so they can adsorb reactant molecules more effectively and promote the catalytic reaction [21,22]. Lee et al developed a binderless spinel oxide nanoparticle-coated nickel foam as an efficient electrocatalyst for water oxidation.…”