title: Single nanoparticle SERS probes of ion intercalation in metal-oxide electrodes.
abstract: Probing ion-intercalating processes in electrodes is hugely important for batteries, supercapacitors, and photovoltaic devices. In this work we use single-nanoparticle (NP) probes to see real-time molecular changes correlated to electrochemically modulated ion-intercalation in metal-oxide electrodes. Using surface-enhanced Raman spectroscopy (SERS) transduced by single NP probes, we observe that the Raman frequencies and spectral intensities of the adsorbed molecules vary on cycling the electrochemical potential on a vanadium-oxide electrode. The potential-dependent frequency shifts in SERS from an electrochemically inert molecule are attributed to a Stark effect induced by chemical and structural changes as a result of ion-intercalation processes in vanadium oxide. Our study opens up a unique strategy to explore adsorbates and molecular reaction pathways on ion-intercalating materials and semiconducting interfaces.
authors.affiliation: Department of Physics, Cavendish Laboratory, University of Cambridge , Cambridge, CB3 0HE, United Kingdom.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Ullrich
authors.initials: U
authors.lastname: Steiner
authors.forename: Sumeet
authors.initials: S
authors.lastname: Mahajan