TY - JOUR
T1 - Real-Space Charge Density Profiling of Electrode-Electrolyte Interfaces with Angstrom Depth Resolution
AU - Bonagiri, Lalith Krishna Samanth
AU - Panse, Kaustubh S.
AU - Zhou, Shan
AU - Wu, Haiyi
AU - Aluru, Narayana R
AU - Zhang, Yingjie
N1 - Funding Information:
L.K.S.B., K.S.P., S.Z., and Y.Z. acknowledge support from the National Science Foundation under Grant No. 2137147. H.W. and N.R.A. acknowledge support from the National Science Foundation under Grant No. 2137157. The experiments were performed in part in the Carl R. Woese Institute for Genomic Biology and in the Materials Research Laboratory at the University of Illinois.
Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/11/22
Y1 - 2022/11/22
N2 - The accumulation and depletion of charges at electrode-electrolyte interfaces is crucial for all types of electrochemical processes. However, the spatial profile of such interfacial charges remains largely elusive. Here we develop charge profiling three-dimensional (3D) atomic force microscopy (CP-3D-AFM) to experimentally quantify the real-space charge distribution of the electrode surface and electric double layers (EDLs) with angstrom depth resolution. We first measure the 3D force maps at different electrode potentials using our recently developed electrochemical 3D-AFM. Through statistical analysis, peak deconvolution, and electrostatic calculations, we derive the depth profile of the local charge density. We perform such charge profiling for two types of emergent electrolytes, ionic liquids, and highly concentrated aqueous solutions, observe pronounced sub-nanometer charge variations, and find the integrated charge densities to agree with those derived from macroscopic electrochemical measurements.
AB - The accumulation and depletion of charges at electrode-electrolyte interfaces is crucial for all types of electrochemical processes. However, the spatial profile of such interfacial charges remains largely elusive. Here we develop charge profiling three-dimensional (3D) atomic force microscopy (CP-3D-AFM) to experimentally quantify the real-space charge distribution of the electrode surface and electric double layers (EDLs) with angstrom depth resolution. We first measure the 3D force maps at different electrode potentials using our recently developed electrochemical 3D-AFM. Through statistical analysis, peak deconvolution, and electrostatic calculations, we derive the depth profile of the local charge density. We perform such charge profiling for two types of emergent electrolytes, ionic liquids, and highly concentrated aqueous solutions, observe pronounced sub-nanometer charge variations, and find the integrated charge densities to agree with those derived from macroscopic electrochemical measurements.
KW - 3D atomic force microscopy
KW - atomic resolution imaging
KW - charging profiling
KW - double layer charging
KW - electric double layer
KW - electrochemical atomic force microscopy
KW - Electrode-electrolyte interface
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U2 - 10.1021/acsnano.2c10819
DO - 10.1021/acsnano.2c10819
M3 - Article
C2 - 36351178
AN - SCOPUS:85142000914
SN - 1936-0851
VL - 16
SP - 19594
EP - 19604
JO - ACS Nano
JF - ACS Nano
IS - 11
ER -