A bioinspired water oxidation catalyst that is ∼1/10 as active as the photosystem II oxygen evolving center at pH 7: a study of activity and stability factors

• Published in: Dalton transactions : an international journal of inorganic chemistry 2024-11, Vol.53 (44), p.17783-17788
• Main Authors: Boskovic, Danijel, Terrett, Richard, Longhurst, Matthew, Basheer, Sabeel, Ariafard, Alireza, Wagner, Pawel, Pace, Ronald J, Stranger, Rob, Swiegers, Gerhard F
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d4dt02336f

The activity and stability of a heterogeneous water oxidation catalyst inspired by the Photosystem II - Oxygen Evolving Center (PSII-OEC) is reported. Ca-doped birnessite MnO x supported on a liquid crystalline reduced graphene oxide (LCrGO) substrate exhibited unprecedented performance for an abiological catalyst at pH 7, including an exceedingly low onset overpotential of 0.52 V ( vs . 0.48 V reported for the PSII-OEC, 0.75 V for Pt, and 0.72 V for birnesite MnO x ) and remarkably high activity per unit area at 0.56 V overpotential (∼10% that of a hypothetical, closely-packed monolayer of OEC sites at their optimum density of 10 14 sites per cm 2 ). Ca-doped birnessite MnO x on liquid crystalline reduced graphene oxide exhibits unprecedented performance for an abiological catalyst at pH 7, including a very low onset overpotential of 0.52 V and high activity per unit area at 0.56 V overpotential.