TY  - JOUR
AU  - Lakner, Pirmin
AU  - Brinker, Manuel
AU  - Seitz, Christoph
AU  - Jacobse, Leon
AU  - Vonk, Vedran
AU  - Lippmann, Milena
AU  - Volkov, Sergey
AU  - Huber, Patrick
AU  - Keller, Thomas F.
TI  - Probing the Electrolyte Transfer in Ultrathin Polypyrrole Films by In Situ X-ray Reflectivity and Electrochemistry
JO  - Langmuir
VL  - 36
IS  - 45
SN  - 1520-5827
CY  - Washington, DC
PB  - ACS Publ.
M1  - PUBDB-2020-04509
SP  - 13448 - 13456
PY  - 2020
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - pmid:33151688
UR  - <Go to ISI:>//WOS:000592840500008
DO  - DOI:10.1021/acs.langmuir.0c02068
UR  - https://bib-pubdb1.desy.de/record/452117
ER  -