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


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
Publication statusPublished - Oct 2019



  • 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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