Electron Tunneling at Electrocatalytic Interfaces

Abstract

It was recently proposed that tunneling current fluctuations in electrochemical scanning tunneling microscopy (EC-STM) can be used to map the electrocatalytic activity of surfaces with high spatial resolution. However, the relation between the increased noise in the electron tunneling signal and the local reactivity for such complex electrode/electrolyte interfaces is only explained qualitatively or hypothetically. Herein, we employ electron transport calculations to examine tunneling at Pt surfaces under the conditions of the oxygen reduction reaction as a case study. By computing current–voltage characteristics, we reveal that the tunneling barrier strongly depends on the chemical identity of the adsorbed reaction intermediate as well as on the orientation of the average dipole moment of water species mediating electron tunneling. Our theoretical results combined with EC-STM measurements suggest that detecting reaction intermediates at electrified interfaces in operando conditions is possible based on tunneling noise amplitudes. This study also aims to stimulate further explorations of tunneling-based electron-proton transfers to enable quantum electrocatalysis beyond conventional approaches.

Enhancing the performance and cyclability of MoS2 cathodes with interspace layer engineering using polypyrrole

“…Aqueous zinc-ion batteries (AZIBs) have attracted considerable interest largely due to their notable features, which encompass a low potential (−0.763 V relative to the standard hydrogen electrode), an abundant supply of resources, non-toxicity, and a theoretically considerable capacity of 5851 mA h cm −3 and 820 mA h g −1 . [15][16][17][18][19][20][21][22][23][24] AZIBs suffer from undesirable practical capacity or unsatisfactory cycle life due to a number of factors, including dendritic formation on the zinc anode, cathode material dissolution, and a sluggish transfer of bivalent Zn 2+ ions within host frameworks. [25][26][27][28][29][30][31] Recent research ndings indicate that the application of aqueous electrolytes characterized by moderate acidity or neutrality can substantially improve the stability of the zinc anode.…”

“…Aqueous zinc-ion batteries (AZIBs) have attracted considerable interest largely due to their notable features, which encompass a low potential (−0.763 V relative to the standard hydrogen electrode), an abundant supply of resources, non-toxicity, and a theoretically considerable capacity of 5851 mA h cm −3 and 820 mA h g −1 . 15–24…”