Covalent Grafting of Ruthenium Complexes on Iron Oxide Nanoparticles: Hybrid Materials for Photocatalytic Water Oxidation

• Published in: ACS applied materials & interfaces 2021-11, Vol.13 (45), p.53829-53840
• Main Authors: Nguyen, Quyen T, Rousset, Elodie, Nguyen, Van T. H, Colliere, Vincent, Lecante, Pierre, Klysubun, Wantana, Philippot, Karine, Esvan, Jérôme, Respaud, Marc, Lemercier, Gilles, Tran, Phong D, Amiens, Catherine
• Format: Article
• Language: English
• Subjects: Energy, Environmental, and Catalysis Applications; Engineering Sciences; Materials
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c15051

The present environmental crisis prompts the search for renewable energy sources such as solar-driven production of hydrogen from water. Herein, we report an efficient hybrid photocatalyst for water oxidation, consisting of a ruthenium polypyridyl complex covalently grafted on core/shell Fe@FeO x nanoparticles via a phosphonic acid group. The photoelectrochemical measurements were performed under 1 sun illumination in 1 M KOH. The photocurrent density of this hybrid photoanode reached 20 μA/cm2 (applied potential of +1.0 V vs reversible hydrogen electrode), corresponding to a turnover frequency of 0.02 s–1. This performance represents a 9-fold enhancement of that achieved with a mixture of Fe@FeO x nanoparticles and a linker-free ruthenium polypyridyl photosensitizer. This increase in performance could be attributed to a more efficient electron transfer between the ruthenium photosensitizer and the Fe@FeO x catalyst as a consequence of the covalent link between these two species through the phosphonate pendant group.