Moment-Tensor-Based Constant-Potential Modeling of Electrical Double Layers

Fuente: arXiv
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Main Authors: Wang, Zhenxiang, Chen, Ming, Wu, Jiedu, Ji, Xiangyu, Zeng, Liang, Peng, Jiaxing, Yan, Jiawei, Kornyshev, Alexei A., Mao, Bingwei, Feng, Guang
Format: Preprint
Published: 2024
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author Wang, Zhenxiang
Chen, Ming
Wu, Jiedu
Ji, Xiangyu
Zeng, Liang
Peng, Jiaxing
Yan, Jiawei
Kornyshev, Alexei A.
Mao, Bingwei
Feng, Guang
author_facet Wang, Zhenxiang
Chen, Ming
Wu, Jiedu
Ji, Xiangyu
Zeng, Liang
Peng, Jiaxing
Yan, Jiawei
Kornyshev, Alexei A.
Mao, Bingwei
Feng, Guang
contents Constant-potential molecular dynamics (MD) simulations are indispensable for understanding the capacitance, structure, and dynamics of electrical double layers (EDLs) at the atomistic level. However, the classical constant-potential method, relying on the so-called 'floating charges' to keep electrode equipotential, overlooks quantum effects on the electrode and always underestimates EDL capacitance for typical electrochemical systems featuring metal electrodes in aqueous electrolytes. Here, we propose a universal theoretical framework as moment-tensor-based constant potential method (mCPM) to capture electronic structure variations with electric moments. For EDLs at Au(111) electrodes, mCPM-based MD reveals bell-shaped capacitance curves in magnitude and shape both quantitatively consistent with experiments. It further unveils the potential-dependent local electric fields, agreeing with experimental observations of redshift vibration of interfacial water under negative polarization and predicting a blueshift under positive polarization, and identifies geometry dependence of two time scales during EDL formation.
format Preprint
id arxiv_https___arxiv_org_abs_2401_17145
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Moment-Tensor-Based Constant-Potential Modeling of Electrical Double Layers
Wang, Zhenxiang
Chen, Ming
Wu, Jiedu
Ji, Xiangyu
Zeng, Liang
Peng, Jiaxing
Yan, Jiawei
Kornyshev, Alexei A.
Mao, Bingwei
Feng, Guang
Chemical Physics
Mesoscale and Nanoscale Physics
Constant-potential molecular dynamics (MD) simulations are indispensable for understanding the capacitance, structure, and dynamics of electrical double layers (EDLs) at the atomistic level. However, the classical constant-potential method, relying on the so-called 'floating charges' to keep electrode equipotential, overlooks quantum effects on the electrode and always underestimates EDL capacitance for typical electrochemical systems featuring metal electrodes in aqueous electrolytes. Here, we propose a universal theoretical framework as moment-tensor-based constant potential method (mCPM) to capture electronic structure variations with electric moments. For EDLs at Au(111) electrodes, mCPM-based MD reveals bell-shaped capacitance curves in magnitude and shape both quantitatively consistent with experiments. It further unveils the potential-dependent local electric fields, agreeing with experimental observations of redshift vibration of interfacial water under negative polarization and predicting a blueshift under positive polarization, and identifies geometry dependence of two time scales during EDL formation.
title Moment-Tensor-Based Constant-Potential Modeling of Electrical Double Layers
topic Chemical Physics
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2401.17145