Abstract
Lindqvist-type polyoxometalates (POMs) derivatized with pyrrole (Py) via an aryl-imido linkage [Mo6O18NPhPy]2- (1) and [Mo6O18NPhCCPhPy]2- (2) undergo coelectropolymerization with pyrrole, producing the first electropolymer films with covalently attached POM "molecular metal oxides". X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) elemental analyses indicate that the loadings of POM achieved are far higher than in conventional, noncovalent inclusion films, and covalent attachment prevents loss of POM on initial reduction cycles. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge measurements together indicate that the POMs enhance the specific capacitance (up to 5×) and decrease the charge-transfer resistance of the films by both modifying the behavior of the polypyrrole (PPy) film and introducing a substantial additional faradaic contribution through the POM redox processes. Increasing the length of the POM-PPy linker improves both capacitance and stability, with PPy-2 retaining 95% of its initial capacitance over 1200 cycles.
Original language | English |
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Pages (from-to) | 11120-11129 |
Number of pages | 10 |
Journal | Macromolecules |
Volume | 53 |
Issue number | 24 |
Early online date | 10 Dec 2020 |
DOIs | |
Publication status | Published - 22 Dec 2020 |
Bibliographical note
Funding Information:We thank Professor Chris Pickett and Dr. Saad Ibrahim of the University of East Anglia for helpful discussions on electropolymerization; Dr. Michael Ward, Dr. Benjamin Johnson, and Dr. Kellye Curtis of LENNF (University of Leeds) for electron microscopy and XPS measurements; and Mr. Bertrand Leze of the University of East Anglia for electron microscopy measurements. A.A.Y. thanks the Iraqi Government for financial support via the Ministry of Higher Education and Scientific Research (MOHER), University of Kerbala, for a postdoctoral fellowship; and S.A.A. thanks Princess Nourah bint Abdulrahman University for a Ph.D. scholarship. This work was also supported by EU FP7 (Marie Curie IOF POMHYDCAT contract 254339 to J.F.), EPSRC (EP/M00452X/1), and the University of East Anglia.
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Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry