title: In situ SHINERS at electrochemical single-crystal electrode/electrolyte interfaces: tuning preparation strategies and selected applications.
abstract: We have studied Au(55 nm)@SiO2 nanoparticles (NPs) on two low-index phases of gold and platinum single crystal electrodes in ClO4(-) and SO4(2-) ion-containing electrolytes by both electrochemical methods and in-situ shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS). We showed the blocking of the electrode with surfactants originating from the synthesis of as-prepared SHINERS NPs. We introduce an efficient procedure to overcome this problem, which provides a fundamental platform for the application of SHINERS in surface electrochemistry and beyond. Our method is based on a hydrogen evolution treatment of the SHINERS-NP-modified single-crystal surfaces. The reliability of our preparation strategy is demonstrated in electrochemical SHINERS experiments on the potential-controlled adsorption and phase formation of pyridine on Au(hkl) and Pt(hkl). We obtained high-quality Raman spectra on these well-defined and structurally carefully characterized single-crystal surfaces. The analysis of the characteristic A1 vibrational modes revealed perfect agreement with the interpretation of single-crystal voltammetric and chronoamperometric experiments. Our study demonstrates that the SHINERS protocol developed in this work qualifies this Raman method as a pioneering approach with unique opportunities for in situ structure and reactivity studies at well-defined electrochemical solid/liquid interfaces.
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern , Freiestrasse 3, Bern, Bern CH-3012, Switzerland.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Li
authors.forename: Alexander
authors.initials: A
authors.lastname: Rudnev
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Fu
authors.forename: Nataraju
authors.initials: N
authors.lastname: Bodappa
authors.forename: Thomas
authors.initials: T
authors.lastname: Wandlowski