%0 Journal Article
%A Lakner, Pirmin
%A Brinker, Manuel
%A Seitz, Christoph
%A Jacobse, Leon
%A Vonk, Vedran
%A Lippmann, Milena
%A Volkov, Sergey
%A Huber, Patrick
%A Keller, Thomas F.
%T Probing the Electrolyte Transfer in Ultrathin Polypyrrole Films by In Situ X-ray Reflectivity and Electrochemistry
%J Langmuir
%V 36
%N 45
%@ 1520-5827
%C Washington, DC
%I ACS Publ.
%M PUBDB-2020-04509
%P 13448 - 13456
%D 2020
%X This study reports on the potential-induced chargeand mass transfer between an ultrathin polypyrrole (PPy)film andan electrolyte by simultaneous in situ X-ray reflectivity (XRR) andelectrochemistry (EC) utilizing their sensitivity to electrons. Anabout 30 nm thin PPyfilm was deposited on a silicon single crystalby fast potential cycling, providing a densefilm of an extraordinarysmall surface roughness. XRR was recorded from the PPyfilm inan aqueous 0.1 M perchloric acid at electric potentials between−0.2 V and +0.5 V vs Ag/AgCl. The PPyfilm shows typicalreversible and linear changes infilm thickness and electron densityarising from the potential-dependent electrolyte incorporation. Byintroducing EC-XRR, a comprehensive analysis combining in situ XRR and EC, the net number of electrons passing through thePPy-electrolyte interface was deduced along with the potential-induced thickness variations, indicating a complex exchangemechanism. Evidently, along with the anion transfer, parallel charge compensation by protons and a volume and electroncompensating counterflow of solvent molecules take place. Complementary time-dependent EC-XRR scans indicate that theseexchange mechanisms are individual in two potential ranges. The low actuation along with a high pseudocapacitance suggest the fastpotentiodynamically deposited PPyfilm as a promising supercapacitor material.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:33151688
%U <Go to ISI:>//WOS:000592840500008
%R 10.1021/acs.langmuir.0c02068
%U https://bib-pubdb1.desy.de/record/452117