Behavior of a Cu-Peptide complex under water oxidation conditions – Molecular electrocatalyst or precursor to nanostructured CuO films?

Dávid Lukács, Miklós Németh, Łukasz Szyrwiel, Levente Illés, Béla Pécz, Shaohua Shen, József S. Pap

Research output: Contribution to journalArticle

Abstract

The true electrocatalyst of water oxidation in a number of cases proved to be an in situ developed ‘CuO’ film instead of (or beside) the original Cu complex itself, since the breaking of metal-ligand interactions under the applied conditions often successfully compete with the homogeneous process. The decomposition of a catalyst candidate is obviously unwanted; on the other hand, inexpensive and controllable precursor complexes represent an exciting platform to fabricate nanostructured metal oxide coatings utilized in artificial photosynthesis. We investigated the Cu-triglycine complex equilibrium system with uniform {N,N,N,O}eq peptide binding mode throughout the pH range of ~7 to 10 in borate buffer. In the presence of the complex under the conditions of water oxidation electrocatalysis the development of a ‘CuO’ nanoparticle coating was observed on the indium tin oxide working electrode. This coating acted as a robust electrocatalyst of water oxidation. X-Ray photoelectron spectroscopy (XPS) indicated a mixed Cu2O/CuO/Cu(OH)2 surface composition. Fine coatings could be also fabricated on different electrodes including glassy carbon, boron-doped diamond and an n-type semiconducting α-Fe2O3 nanoarray, importantly, without ruining its morphology. We identified the interplay between the co-existent borate equilibrium species and the Cu-triglycine system as the key factor to define the dominant process and allow control over the deposition.

Original languageEnglish
Article number110079
JournalSolar Energy Materials and Solar Cells
Volume201
DOIs
Publication statusPublished - Oct 2019

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Keywords

  • Cu complex
  • Electrodeposition
  • Peptide
  • Precursor complex
  • Water oxidation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films

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