Preprint,
Electrodeposition of tunable Cu-Ag nanostructures in a deep eutectic solvent
Contributors
Plaza-Mayoral, Elena
0000-0001-7208-7940
[1]
Dalby, Kim Nicole
0000-0001-6048-3583
[2]
Falsig, Hanne
0000-0002-2474-4093
[2]
Chorkendorff, I B
0000-0003-2738-0325
[3]
Sebastián-Pascual, Paula
0000-0001-7985-0750
[1]
Escudero-Escribano, Marı A
0000-0002-6432-3015
[4]
[5]
Affiliations
- [1] University of Copenhagen [NORA names: KU University of Copenhagen; University; Denmark; Europe, EU; Nordic; OECD];
- [2] Haldor Topsoe (Denmark) [NORA names: Topsoe; Private Research; Denmark; Europe, EU; Nordic; OECD];
- [3] Technical University of Denmark [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD];
- [4] Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, Barcelona Institute of Science and Technology, UAB Campus, 08193 Bellaterra, Barcelona, Spain [NORA names: Spain; Europe, EU; OECD];
- [5] Institució Catalana de Recerca i Estudis Avançats [NORA names: Spain; Europe, EU; OECD]
Abstract
The green transition requires the preparation of clean, inexpensive, and sustainable strategies to prepare controllable bimetallic and multimetallic nanostructures. Cu-Ag nanostructures, for example, are promising bimetallic catalysts for different electrocatalytic reactions such as carbon monoxide and carbon dioxide reduction. In this work, we present the one-step preparation method of electrodeposited Cu-Ag with tunable composition and morphology from choline chloride plus urea deep eutectic solvent (DES), a non-toxic and green DES. We have assessed how different electrodeposition parameters affect the morphology and composition of our nanostructures. We combine electrochemical methods with ex-situ scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) to characterize the nanostructures. We have estimated the electrochemically active surface area (ECSA) and roughness factor (R) by lead underpotential deposition (UPD). The copper/silver ratio in the electrodeposited nanostructures is highly sensitive to the applied potential, bath composition, and loading. We observed that silver-rich nanostructures were less adherent whereas the increase in copper content led to more stable and homogenous films with disperse rounded nanostructures with tiny spikes. These spikes were more stable when the deposition rate was fast enough and the molar ratio of Cu and Ag no greater than approximately two to one.
