Preparation of a Dual‐MOF Heterostructure (ZIF@MIL) for Enhanced Oxygen Evolution Reaction Activity

Abstract

Although metal‐organic frameworks have proven to be excellent electrocatalytic materials, their application as electrode materials remains limited. The preparation of heterostructures is considered an effective method to improve catalytic activity. Herein, we describe the design and assembly of a dual‐MOF heterostructure (CoNi−ZIF‐67@Fe−MIL‐100, denoted ZIF@MIL). Specifically, we grew a layer of MIL‐100 in situ on a bimetallic ZIF‐67 surface using a solvothermal method. We demonstrate that the ZIF@MIL has remarkable OER electrocatalytic performance, requiring a low overpotential and showing a small Tafel slope, compared to pure ZIF‐67 and MIL‐100 in 1.0 m KOH. More importantly, it has excellent operational durability for 50 h at 100 mA cm−2. The high catalytic activity of ZIF@MIL can be attributed to the heterostructure that can expose more active sites, the synergistic effect between ZIF‐67 and MIL‐100, and improvement of electron transfer ability. Our work provides a new way to design and prepare dual‐MOF crystals with different structures as electrocatalysts.

Hetero MOF‐on‐MOF‐derived carbon nanotube interconnected nitrogen‐doped carbon‐encapsulated FeNi/FeF2 for efficient oxygen evolution reaction

“…310 mV was still required to obtain a current density of 10 mA cm −2 33 . Nickel–iron composites were regarded as one of the most promising electrocatalysts for the OER due to the efficient Fe and Ni synergism, 34 and the Fe/Ni‐based MIL (MIL represents Materials of Institut Lavoisier) MOF was thus promising for the development of OER catalysts 30 . While the above‐mentioned problems like instability and low conductivity are still not well solved even for derivatives of the Fe/Ni‐based MOF catalyst, the combined approach using an inactive MOF to increase the conductivity and stability might be valid for structure modification without complicating the derived Fe/Ni catalyst system for the catalytic ability optimization.…”

“…[24][25][26] Though there are many reports of MOF-derived catalysts like the above-mentioned phosphides, sulfides, and selenides, the pitfalls of low active site exposure and delayed active phase formation, as well as the low charge-transfer ability, still remain, [27][28][29] especially for the single metal-based derivatives. Fortunately, heterostructure-based MOFs have been found to be efficient in increasing the active site exposure, charge transfer, and active site synergism [30][31][32] because of the combined merits of each component material and composited property of the hybrid system. For example, CoP nanoparticles embedded in a N-doped carbon nanotube hollow polyhedron were fabricated from the hybrid MOFs of core-shelled ZIF-8@ZIF-67, and they showed good bifunctional electrocatalytic performances for a water-splitting reaction, but a high overpotential of ca.…”

“…33 Nickel-iron composites were regarded as one of the most promising electrocatalysts for the OER due to the efficient Fe and Ni synergism, 34 and the Fe/Nibased MIL (MIL represents Materials of Institut Lavoisier) MOF was thus promising for the development of OER catalysts. 30 While the above-mentioned problems like instability and low conductivity are still not well solved even for derivatives of the Fe/Ni-based MOF catalyst, the combined approach using an inactive MOF to increase the conductivity and stability might be valid for structure modification without complicating the derived Fe/Ni catalyst system for the catalytic ability optimization. Zn-zeolite imidazolate frameworks (ZIFs) come into our minds because of not only the good chemical stability for crystal structure formation with organic ligands 33 but also porous structure formation due to the volatile Zn vapor during pyrolysis (greater than 907°C).…”

Metal‐Organic‐Framework‐Based Single‐Atomic Catalysts for Energy Conversion and Storage: Principles, Advances, and Theoretical Understandings

“…Although their metal loading is usually low, enhanced catalytic performance can also be achieved by making full use of the metal active sites. [19] To date, SACs have been extensively studied in ORR, [48] oxygen evolution reaction (OER), [49] HER, [23b] CO 2 reduction reaction (CO 2 RR), [50] and batteries. [51] In the following section, we will discuss in detail the various applications of single-atom catalysts.…”

The synthesis of zeolitic imidazolate framework/prussian blue analogue heterostructure composites and their application in supercapacitors

“…23,24 This integration was usually prepared through the growth guest MOFs on pre-synthesized host MOFs or growth kinetic controlled routes by various chemical interactions, including epitaxial growth, surfactant assisted growth, ligand/metal ion exchange and so on. 25,26 To date, heterostructure composites have various architectures such as core-shell, core-satellite, hollow multi-shell, and asymmetric structures, which resulted from the combination of different functional materials. 27,28 The complex structure of dual-MOF heterostructure composites not only showed structural diversity, but also had considerable potential in practical applications when compared with those of original MOF materials, especially in energy storage.…”