In Situ Spectroscopic Studies Of Electrocatalytic Electrodes

Author : Guangyan Zhong
Publisher :
ISBN 13 :
Total Pages : 98 pages
Book Rating : 4.:/5 (129 download)

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Download or read book Electrical Transport Spectroscopy (ETS) for In Situ Probing Electrode-Electrolyte Interfaces written by Guangyan Zhong and published by . This book was released on 2021 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemistry of metallic nanostructures has played an essential role in a wide range of energy-related technologies. A fundamental understanding of the electrocatalytic surface is crucial for developing future generations of electrocatalysts with improved catalytic activity. Various spectroscopy-based methods have been applied in electrochemical surface studies, but most of these techniques are limited to ex-situ studies. In situ monitoring of catalytic interface during the electrochemical process is considered most informative yet extremely challenging. The fact that electrochemical interfaces are buried between the solid electrode and liquid electrolyte makes them difficult to access by traditional spectroscopic method. Methods that are able to circumvent these challenges often require unusual device design or highly complicated facilities.Our group specifically designed Electrical transport spectroscopy (ETS) for in situ monitor of electrochemical interfaces. When the dimension of a metallic structure decreases to the mean free path of the electrons within it, the diffusive scattering induced by the surface adsorbates can produce a significant change in resistivity. During an electrochemical cycle, the specifixally adsorbed molecules on the nanocatalysts surface could produce a detectable conductance change, providing an effective signaling pathway for in situ probing different molecular species at the electrode-electrolyte interface during the electrochemical process. With this novel nanoelectronic measurement approach, we can conduct a series of systematic investigations of nano- electrocatalysts surface chemistry for a wide range of fundamentally or practically important electrocatalytic reactions. In this thesis, I will present three examples utilizing ETS for the in-situ characterization of the electrode-electrolyte interfaces. First, we investigated competitive anionic chemisorption on the platinum surface and its relationship with ORR kinetics on Pt (Chapter 2). Nest, we acquired ETS results under controlled potential range in a serials of pH conditions, which allows to determine the pKa of hydronium adsorbed on the platinum surface for interpreting distinct hydrogen evolution reaction kinetics at different pH (Chapter 3). Lastly, we explored the ETS approach sensing applciations including their potential for the detection of hydrogen peroxide and DNA molecules (Chapter 4).