Pushing the limits in photosensitizer-catalyst interaction via a short cyanide bridge for water oxidation

Ghobadi T. G. U., Ghobadi A., Demirtas M., Phul R., Yildiz E., YAĞLIOĞLU H. G., ...More

CELL REPORTS PHYSICAL SCIENCE, vol.2, no.2, 2021 (ESCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 2 Issue: 2
  • Publication Date: 2021
  • Doi Number: 10.1016/j.xcrp.2020.100319
  • Journal Name: CELL REPORTS PHYSICAL SCIENCE
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus, Directory of Open Access Journals
  • Ankara University Affiliated: Yes

Abstract

The realization of high-performance, precious-metal-free, stable, and robust photoanodes for water oxidation is one of the bottlenecks for dye-sensitized water splitting. Herein, we integrate an organic photosensitizer, which absorbs visible light above 500 nm, with a Prussian blue (PB) network to sensitize a visible-light-absorbing semiconductor, WO3. Through comprehensive steady-state and ultrafast transient absorption studies, we show that the coupling of a photosensitizer to a catalyst through a short cyanide bridging group in a PB structure generates appropriate energy levels for an efficient charge transfer from the photosensitizer to the visible-light-absorbing semiconductor. The photoanode retains its structural integrity and high photoelectrochemical activity for at least 2 h of solar irradiation under mildly acidic conditions (pH 3), which reaches around 1.30 mA/cm(2) at 1.23 V-RHE. This work provides a simple recipe with a toolbox that can be extended to a variety of organic photosensitizers and semiconductors.