Current Progress in 2D Metal–Organic Frameworks for Electrocatalysis

Abstract

The 2D nanosheets of metal–organic frameworks (MOFs) have recently emerged as a promising material that makes them valuable in widespread electrocatalytic fields due to their atomic‐level thickness, abundant active sites, and large surface area. Efficient electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting are highly desired with low overpotentials to promote the industrial applications of energy conversion and devices. 2D MOF nanostructures provide long‐term stability and high electrical conductivity to enhance catalyst activity and durability. This review briefly summarizes the synthesis and electrocatalytic applications of 2D MOF for HER/OER/water splitting. More attention is focused on the synthetic strategies of 2D MOF and their derivatives. The catalytic performance and superior properties of these materials are highlighted. The outperformance of these materials originates from the rational design, myriad of abundant active sites, and atomic‐level thickness. The current and future challenges in this field and the scientific perspectives to overcome these challenges are highlighted. It is suggested that the construction of 2D MOF nanostructures can develop a state‐of‐the‐art electrocatalyst in energy and environmental division.

EC-MOF/Phase-I: A computationally ready database of electrically conductive metal-organic frameworks with high-throughput structural and electronic properties

“…Consequently, monolayer materials exfoliated from their corresponding bulk systems may possess unconventional properties in the fields of gas adsorption, 57 optics 58 and electrocatalysis. 59 EC-MOF monolayers can be synthesized through top-down or bottom-up approaches. Chemical exfoliation methods such as intercalation and electrochemical exfoliation are among the most common techniques in the top-down strategy.…”

“…58 On the contrary, bottom-up approach is a more efficient and convenient approach to build mono-layer materials by choosing ideal precursors, modulators and surfactants. 59 To shed light on the possibility of reaching at a mono-layer EC-MOF, we have calculated the inter-layer binding energies (E b ) according to Eq. 2 for all structures gathered in EC-MOF/Phase-I database.…”

Regulating the coordination environment of a metal–organic framework for an efficient electrocatalytic oxygen evolution reaction

“…[34][35][36][37][38][39] However, in the structure of MOFs, the metal nodes are surrounded by organic linking groups, 40 which limits their catalytic activity and conductivity; 41 thereby, it is vital to construct these structures with a rational design. [42][43][44][45] In terms of macrostructure control, 46 Lou et al typically construct a unique core-shell structure through chemical etching methods and other methods, 47 which could provide a larger catalytic interface area, 48 thereby significantly improving the electrocatalytic performance. 49 Li et al used carbonization to precisely regulate Hofmann-type MOFs into different forms (including nanosheets, nanoflowers, 50 nanotubes and aggregates), which OER catalytic performance far exceeds that of commercial RuO 2 catalysts.…”

Improved Interface Stability and Zinc‐Ions Distribution Achieved by Functional Protective Layer Containing Abundant Oxygen Sites and Regular Channels for Long‐Life Zinc‐Metal Anodes

“…Therefore, constructing an artificial protective layer on Zn metal is necessary for stabilizing the electrode interface and suppressing the growth of Zn dendrites. [32,33] Recently, some works have reported that nano-CaCO 3 thin layer, [34] ZnF 2 coating [35] and other insulating protective layers prepared by the technology of atomic layer deposition [36] or direct covering [37] can effectively prolong the lifespan and improve cycling stability of Zn metal anode. However, due to the introduction of an additional layer on the Zn electrode, an annoying problem that prepared artificial protective layers usually deliver the sluggish transference of Zn ions may result in the increase of interfacial voltage polarization during the Zn deposition/dissolution process.…”