title: Electrochemical water oxidation with carbon-grafted iridium complexes.
abstract: Hydrogen production from water splitting provides a potential solution to storing harvested solar energy in chemical fuels, but this process requires active and robust catalysts that can oxidize water to provide a source of electrons for proton reduction. Here we report the direct, covalent grafting of molecular Ir complexes onto carbon electrodes, with up to a monolayer coverage. Carbon-grafted Ir complexes electrochemically oxidize water with a turnover frequency of up to 3.3 s(-1) and a turnover number of 644 during the first hour. Electrochemical water oxidation with grafted catalysts gave enhanced rates and stability compared to chemically driven water oxidation with the corresponding molecular catalysts. This strategy provides a way to systematically evaluate catalysts under tunable conditions, potentially providing new insights into electrochemical water oxidation processes and water oxidation catalyst design.
authors.affiliation: Department of Chemistry, CB#3290, University of North Carolina, Chapel Hill, North Carolina 27599, United States.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: deKrafft
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Xie
authors.forename: Xin
authors.initials: X
authors.lastname: Su
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Hinds
authors.forename: Wenbin
authors.initials: W
authors.lastname: Lin
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D007495:Iridium / Q000737:chemistry*; D010084:Oxidation-Reduction; D014867:Water / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D014867:Water; D007495:Iridium; D002244:Carbon