Contact Electrification via Redox‐Active Molecules
Abstract
Abstract Contact electrification, as the transfer of charge upon the contact of two (dis)similar materials, is strongly influenced by surface chemistry, which governs the efficiency of charge separation. For harvesting electrical energy from mechanical energy, material pairs with high electron‐transfer efficiency are essential. Here, we introduce a strategy to use electronic charge transfer in contact electrification via surface functionalization with redox‐active organic molecules. Specifically, we functionalize Au(111) surfaces with mercaptomethyl‐terminated redox‐active molecules, namely triphenylamine and tetrathiafulvalene as donors and 11,11,12,12‐tetracyano‐9,10‐anthraquinodimethane as an acceptor, achieving stable and covalent immobilization, as confirmed by X‐ray photoelectron spectroscopy, electrochemical characterization, and density functional theory calculations, and enabling molecular‐level electron‐transfer. To quantify charge transfer at the micrometer scale, we introduce a contact electrification assay combining atomic force microscopy‐based force spectroscopy and Kelvin probe force microscopy. This approach allows for a precise measurement of charge transfer between Au(111) surfaces functionalized with redox‐active molecules, revealing an electron‐driven mechanism capable of achieving surface charge densities of (120 ± 17) µC m −2 . Our findings deepen the fundamental understanding of contact electrification by demonstrating that electron transfer—depending on the choice of materials—can indeed be its origin, and pave the way for the development of more efficient triboelectric devices.
Article Details
Authors (15)
Nisha Ranjan
Institute of Physical Chemistry University of Freiburg Albertstr. 21 79104 Freiburg Germany
Zohreh Izadi
Cluster of Excellence <i>liv</i>MatS @ FIT – Freiburg Center for Interactive Materials and Bioinspired Technologies University of Freiburg Georges‐Köhler‐Allee 105 79110 Freiburg Germany
Philipp Gaiser
Cluster of Excellence <i>liv</i>MatS @ FIT – Freiburg Center for Interactive Materials and Bioinspired Technologies University of Freiburg Georges‐Köhler‐Allee 105 79110 Freiburg Germany
María B. Camarada
Cluster of Excellence <i>liv</i>MatS @ FIT – Freiburg Center for Interactive Materials and Bioinspired Technologies University of Freiburg Georges‐Köhler‐Allee 105 79110 Freiburg Germany
Rekha Sharma
Cluster of Excellence <i>liv</i>MatS @ FIT – Freiburg Center for Interactive Materials and Bioinspired Technologies University of Freiburg Georges‐Köhler‐Allee 105 79110 Freiburg Germany
Andrej Weber
Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
Michael Daub
Inorganic Functional Materials and Nanomaterials, Institute of Inorganic and Analytical Chemistry University of Freiburg Albertstr. 21 79104 Freiburg Germany
Qiwei Hu
Institute of Physical Chemistry University of Freiburg Albertstr. 21 79104 Freiburg Germany
Michael Fiederle
Freiburg Materials Research Center (FMF) University of Freiburg Stefan‐Meier‐Str. 21 79104 Freiburg Germany
Leonard Mayrhofer
Fraunhofer IWM Wöhlerstr. 11 79108 Freiburg Germany
Michael Moseler
Cluster of Excellence <i>liv</i>MatS @ FIT – Freiburg Center for Interactive Materials and Bioinspired Technologies University of Freiburg Georges‐Köhler‐Allee 105 79110 Freiburg Germany
Anna Fischer
Michael Walter
Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT)
Birgit Esser
Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
Bizan N. Balzer
Institute of Physical Chemistry, Albertstr. 21, 79104 Freiburg, Germany