TY - JOUR
T1 - Monitoring Local Electric Fields using Stark Shifts on Napthyl Nitrile-Functionalized Silicon Photoelectrodes
AU - Shi, Haotian
AU - Pekarek, Ryan T.
AU - Chen, Ran
AU - Zhang, Boxin
AU - Wang, Yu
AU - Aravind, Indu
AU - Cai, Zhi
AU - Jensen, Lasse
AU - Neale, Nathan R.
AU - Cronin, Stephen B.
N1 - Funding Information:
This research was supported by the National Science Foundation (NSF) award no. 1708581 (H.S.) and CBET-1512505 (B.Z.), the Army Research Office (ARO) award no. W911NF-17-1-0325 (Y.W.), the Air Force Office of Scientific Research (AFOSR) grant no. FA9550-19-1-0115 (I.A.), and the Department of Energy (DOE) award no. DE-SC0019322 (Z.C.). L.J. and R.C. acknowledge the support from the National Science Foundation Grant CHE-1707657. Portions of this work were conducted with Advanced Cyberinfrastructure computational resources provided by the Institute for Cyber-Science at the Pennsylvania State University ( https://ics.psu.edu/ ). This work was conducted in part by the Alliance for Sustainable Energy, LLC, the manager and operator of the National Renewable Energy Laboratory for the U.S. Department of Energy (DOE) under Contract no. DE-AC36-08GO28308. Funding for molecular functionalization of a silicon surface and paper preparation was provided by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, Solar Photochemistry Program. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. government. The publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. government purposes.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/8/6
Y1 - 2020/8/6
N2 - We report spectroscopic measurements of the local electric field using vibrational Stark shifts of napthyl nitrile-functionalized silicon under electrochemical working conditions. The CN bond is particularly sensitive to applied electric fields and serves as a good probe for the local electric fields at the silicon-aqueous interface. Here, surface-enhanced Raman spectra (SERS) are collected at a silicon surface using a water immersion lens as a function of the reference potential in a three-terminal potentiostat. In deionized (DI) water and KCl solutions, the nitrile (i.e., CN) stretch downshifts by 4.7 and 8.6 cm-1, respectively, under an applied potential of-1 V vs Ag/AgCl. Density functional theory (DFT) calculations of the napthyl nitrile complex carried out under various electric fields establish the Stark tuning rate to be 0.5622 cm-1/(MV cm-1). Based on this relation, electric fields of-8.4 and-15.2 MV/cm were obtained under negative applied potentials. These measurements report the electric field strength within the double (i.e., Helmholtz) layer, which is responsible for pulling positively charged ions (e.g., H+) toward the surface in reduction reaction processes.
AB - We report spectroscopic measurements of the local electric field using vibrational Stark shifts of napthyl nitrile-functionalized silicon under electrochemical working conditions. The CN bond is particularly sensitive to applied electric fields and serves as a good probe for the local electric fields at the silicon-aqueous interface. Here, surface-enhanced Raman spectra (SERS) are collected at a silicon surface using a water immersion lens as a function of the reference potential in a three-terminal potentiostat. In deionized (DI) water and KCl solutions, the nitrile (i.e., CN) stretch downshifts by 4.7 and 8.6 cm-1, respectively, under an applied potential of-1 V vs Ag/AgCl. Density functional theory (DFT) calculations of the napthyl nitrile complex carried out under various electric fields establish the Stark tuning rate to be 0.5622 cm-1/(MV cm-1). Based on this relation, electric fields of-8.4 and-15.2 MV/cm were obtained under negative applied potentials. These measurements report the electric field strength within the double (i.e., Helmholtz) layer, which is responsible for pulling positively charged ions (e.g., H+) toward the surface in reduction reaction processes.
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U2 - 10.1021/acs.jpcc.0c03966
DO - 10.1021/acs.jpcc.0c03966
M3 - Article
AN - SCOPUS:85091143367
VL - 124
SP - 17000
EP - 17005
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 31
ER -