Time-Resolved Electrochemical Impedance Spectroscopy of Stochastic Nanoparticle Collision: Short Time Fourier Transform versus Continuous Wavelet Transform

Long Duong Ha; Ki Jun Kim; Seong Jung Kwon; Byoung-Yong Chang; Seongpil Hwang

doi:10.1002/smll.202302158

Time-Resolved Electrochemical Impedance Spectroscopy of Stochastic Nanoparticle Collision: Short Time Fourier Transform versus Continuous Wavelet Transform

Small. 2023 Aug;19(33):e2302158. doi: 10.1002/smll.202302158. Epub 2023 May 10.

Authors

Long Duong Ha¹, Ki Jun Kim², Seong Jung Kwon², Byoung-Yong Chang³, Seongpil Hwang¹

Affiliations

¹ Department of Advanced Materials Chemistry, Korea University, Sejong, 30019, South Korea.
² Department of Chemistry, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea.
³ Department of Chemistry, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513, South Korea.

PMID: 37162441
DOI: 10.1002/smll.202302158

Abstract

This work demonstrates the utilization of short-time Fourier transform (STFT), and continuous wavelet transform (CWT) electrochemical impedance spectroscopy (EIS) for time-resolved analysis of stochastic collision events of platinum nanoparticles (NPs) onto gold ultramicroelectrode (UME). The enhanced electrocatalytic activity is observed in both chronoamperometry (CA) and EIS. CA provides the impact moment and rough estimation of the size of NPs. The quantitative information such as charge transfer resistance (R_ct ) relevant to the exchange current density of a single Pt NP is estimated from EIS. The CWT analysis of the phase angle parameter is better for NP collision detection in terms of time resolution compared to the STFT method.

Keywords: Fourier transform; Pt nanoparticles; continuous wavelet transform; electrochemical impedance spectroscopy; single nanoparticles; single-entity electrochemistry; time-resolved.

Abstract

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