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Understanding and Optimizing Ultra‐Thin Coordination Polymer Derivatives with High Oxygen Evolution Performance
Author(s) -
Zhao Yonggui,
Wan Wenchao,
Chen Yi,
Erni Rolf,
Triana Carlos A.,
Li Jingguo,
Mavrokefalos Christos K.,
Zhou Ying,
Patzke Greta R.
Publication year - 2020
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202002228
Subject(s) - overpotential , oxygen evolution , materials science , catalysis , electron transfer , density functional theory , polymer , rational design , chemical engineering , x ray absorption spectroscopy , thin film , nanotechnology , chemistry , absorption spectroscopy , computational chemistry , organic chemistry , electrochemistry , electrode , composite material , engineering , physics , quantum mechanics
Engineering low‐crystalline and ultra‐thin nanostructures into coordination polymer assemblies is a promising strategy to design efficient electrocatalysts for energy conversion and storage. However, the rational utilization of coordination polymers (CPs) or their derivatives as electrocatalysts has been hindered by a lack of insight into their underlying catalytic mechanisms. Herein, a convenient approach is presented where a series of Ni 10‐x Fe x ‐CPs (0 ≤ x ≤ 5) is first synthesized, followed by the introduction of abundant structural deficiencies using a facile reductive method (R‐Ni 10‐x Fe x ‐CPs). The representative low‐crystalline R‐Ni 8 Fe 2 ‐CPs (R‐NiFe‐CPs) with a thickness of sub‐2 nm display promising oxygen evolution reaction (OER) performance with a very low overpotential of 225 mV at 10 mA cm −2 and high long‐term durability over 120 h. Comprehensive investigations including X‐ray absorption spectroscopy, density functional theory, and mass diffusion theory reveal strong synergistic effects of structural deficiencies on the OER activity. A super‐Nernstian pH‐dependence of 85.15 mV pH −1 suggests that the catalytic OER mechanism of R‐NiFe‐CPs involved a decoupled proton‐electron transfer (PT/ET) pathway, leading to notably higher OER activity compared to the concerted coupled proton‐electron transfer pathway. New insights into the catalytic reaction mechanisms of CP‐related materials open up new approaches to expedite the design of efficient electrocatalysts.