A Molecular Z-Scheme Artificial Photosynthetic System Under the Bias-Free Condition for CO2 Reduction Coupled with Two-electron Water Oxidation: Photocatalytic Production of CO/HCOOH and H2 O2

Fazalurahman Kuttassery; Yutaka Ohsaki; Arun Thomas; Ryutaro Kamata; Yosuke Ebato; Hiromu Kumagai; Ryosuke Nakazato; Abin Sebastian; Siby Mathew; Hiroshi Tachibana; Osamu Ishitani; Haruo Inoue

doi:10.1002/anie.202308956

A Molecular Z-Scheme Artificial Photosynthetic System Under the Bias-Free Condition for CO₂ Reduction Coupled with Two-electron Water Oxidation: Photocatalytic Production of CO/HCOOH and H₂ O₂

Angew Chem Int Ed Engl. 2023 Oct 2;62(40):e202308956. doi: 10.1002/anie.202308956. Epub 2023 Aug 24.

Authors

Affiliations

¹ Department of Chemistry, University of Calicut, Malappuram, Kerala, 673635, India.
² Department of Applied Chemistry for Environment, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami Osawa, Hachioji, Tokyo, 192-0397, Japan.
³ Department of Chemistry, St. Stephen's College, Uzhavoor, Kerala, 686634, India.
⁴ Department of Chemistry, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro, Tokyo, 152-8550, Japan.
⁵ Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8904, Japan.
⁶ Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526, Japan.

PMID: 37493175
DOI: 10.1002/anie.202308956

Abstract

Bio-inspired molecular-engineered systems have been extensively investigated for the half-reactions of H₂ O oxidation or CO₂ reduction with sacrificial electron donors/acceptors. However, there has yet to be reported a device for dye-sensitized molecular photoanodes coupled with molecular photocathodes in an aqueous solution without the use of sacrificial reagents. Herein, we will report the integration of Sn^IV - or Al^III -tetrapyridylporphyrin (SnTPyP or AlTPyP) decorated tin oxide particles (SnTPyP/SnO₂ or AlTPyP/SnO₂ ) photoanode with the dye-sensitized molecular photocathode on nickel oxide particles containing [Ru(diimine)₃ ]²⁺ as the light-harvesting unit and [Ru(diimine)(CO)₂ Cl₂ ] as the catalyst unit covalently connected and fixed within poly-pyrrole layer (RuCAT-RuC₂ -PolyPyr-PRu/NiO). The simultaneous irradiation of the two photoelectrodes with visible light resulted in H₂ O₂ on the anode and CO, HCOOH, and H₂ on the cathode with high Faradaic efficiencies in purely aqueous conditions without any applied bias is the first example of artificial photosynthesis with only two-electron redox reactions.

Keywords: CO2 Reduction; Photocatalytic Reactions; Photoelectrochemical Cell; Selective Formation of H2O2; Water Oxidation.

Abstract

Grants and funding