Random Occupation of Multimetal Sites in Transition Metal‐Organic Frameworks for Boosting the Oxygen Evolution Reaction

Abstract

Developing robust oxygen evolution reaction (OER) electrocatalysts with excellent performance is essential for the conversion of renewable electricity to clean fuel. Herein, we present a facile concept for the synthesis of efficient highentropy metal-organic frameworks (HEMOFs) as electrocatalysts in a one-step solvothermal synthesis. This strategy allows control of the microstructure and corresponding lattice distortion by tuning the metal ion composition. As a result, the OER activity was improved by optimizing the coordination environment of the metal catalytic center. The optimized Corich HEMOFs exhibited a low overpotential of 310 mV at a current density of 10 mA cm À 2 , better than a RuO 2 catalyst tested under the same conditions. The finding of lattice distortion of the HEMOFs provides a new strategy for developing high-performance electrocatalysts for energy conversion.

Emerging high-entropy coordination compounds and their derivatives for energy application

“…41 Interestingly, Table 1 shows that most HE-MOF materials can be used as pristine or as MOF-derived electrode materials for the OER. MOFs are typically composed of 1,4-benzenedicarboxylate as a linker 9,42–44 and various salts, such as chlorides, acetates, acetyl acetates, and nitrates 9,42–46 as metal precursors. Besides, we can find that the metal precursors used more are based on Co, Ni, Fe, Cu and Mn, and the precursors used less are based on Al, Zn and Mo (Table 1).…”

High‐Entropy Catalyst—A Novel Platform for Electrochemical Water Splitting

“…Reproduced with permission. [ 189 ] Copyright 2022, Wiley‐VCH GmbH. d) The formation of oxygen vacancies in (Co 0.25 Mn 0.25 Ni 0.25 Fe 0.25 )Fe 2 O 4 and (Co 0.2 Mn 0.2 Ni 0.2 Fe 0.2 Zn 0.2 )Fe 2 O 4 due to the lattice distortion.…”

“…As pictured in Figure 12c, introducing multi‐component metallic sites at random in MOFs can form an unsaturated coordination environment due to partial lattice distortion. [ 189 ] Accordingly, the lattice distortion firstly was confirmed via XRD. The electronic structure and the coordination environment were modified, which shows the distortion once again, as determined by XPS.…”

“…c) The unsaturated coordination environment of active sites in HE MOFs. Reproduced with permission [189]. Copyright 2022, Wiley-VCH GmbH.d) The formation of oxygen vacancies in (Co 0.25 Mn 0.25 Ni 0.25 Fe 0.25 )Fe 2 O 4 and (Co 0.2 Mn 0.2 Ni 0.2 Fe 0.2 Zn 0.2 )Fe 2 O 4 due to the lattice distortion.Reproduced with permission [190].…”

Photocatalytic Valorization of Plastic Waste over Zinc Oxide Encapsulated in a Metal–Organic Framework

“…Metal-organic frameworks (MOFs), as an expanding class of porous materials, have been extensively studied. [14][15][16] In recent years, MOFs, including MIL-125(Ti)-NH 2 , [17] MIL-101(Fe)-NH 2 , [18] and UiO66-NH 2 , [19] have been used as novel photocatalysts in the fields of organic oxidation, CO 2 reduction, water splitting, and NO x reduction. [20] Nevertheless, MOFs as photocatalysts still suffer from the unsatisfied photogenerated carrier separation rate, which presents a significant barrier to improving photocatalytic activity.…”