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Strain Regulation to Optimize the Acidic Water Oxidation Performance of Atomic‐Layer IrO x
Author(s) -
Meng Ge,
Sun Wenming,
Mon Aye Aye,
Wu Xuan,
Xia Longyu,
Han Aijuan,
Wang Yu,
Zhuang Zhongbin,
Liu Junfeng,
Wang Dingsheng,
Li Yadong
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201903616
Subject(s) - materials science , overpotential , layer (electronics) , catalysis , substrate (aquarium) , bond length , density functional theory , strain (injury) , layer by layer , chemical engineering , nanotechnology , crystallography , chemistry , computational chemistry , electrochemistry , medicine , biochemistry , oceanography , electrode , geology , crystal structure , engineering
Strain regulation has become an important strategy to tune the surface chemistry and optimize the catalytic performance of nanocatalysts. Herein, the construction of atomic‐layer IrO x on IrCo nanodendrites with tunable IrO bond length by compressive strain effect for oxygen evolution reaction (OER) in acidic environment is demonstrated. Evidenced from in situ extended X‐ray absorption fine structure, it is shown that the compressive strain of the IrO x layer on the IrCo nanodendrites decreases gradually from 2.51% to the unstrained state with atomic layer growth (from ≈2 to ≈9 atomic layers of IrO x ), resulting in the variation of the IrO bond length from shortened 1.94 Å to normal 1.99 Å. The ≈3 atomic‐layer IrO x on IrCo nanodendrites with an IrO bond length of 1.96 Å (1.51% strain) exhibits the optimal OER activity compared to the higher‐strained (2.51%, ≈2 atomic‐layer IrO x ) and unstrained (>6 atomic‐layer IrO x ) counterparts, with an overpotential of only 247 mV to achieve a current density of 10 mA cm −2 . Density functional theory calculations reveal that the precisely tuned compressive strain effect balances the adsorbate–substrate interaction and facilitates the rate‐determining step to form HOO*, thus assuring the best performance of the three atomic‐layer IrO x for OER.