title: Protein delivery of a Ni catalyst to photosystem I for light-driven hydrogen production.
abstract: The direct conversion of sunlight into fuel is a promising means for the production of storable renewable energy. Herein, we use Nature's specialized photosynthetic machinery found in the Photosystem I (PSI) protein to drive solar fuel production from a nickel diphosphine molecular catalyst. Upon exposure to visible light, a self-assembled PSI-[Ni(P2(Ph)N2(Ph))2](BF4)2 hybrid generates H2 at a rate 2 orders of magnitude greater than rates reported for photosensitizer/[Ni(P2(Ph)N2(Ph))2](BF4)2 systems. The protein environment enables photocatalysis at pH 6.3 in completely aqueous conditions. In addition, we have developed a strategy for incorporating the Ni molecular catalyst with the native acceptor protein of PSI, flavodoxin. Photocatalysis experiments with this modified flavodoxin demonstrate a new mechanism for biohybrid creation that involves protein-directed delivery of a molecular catalyst to the reducing side of Photosystem I for light-driven catalysis. This work further establishes strategies for constructing functional, inexpensive, earth-abundant solar fuel-producing PSI hybrids that use light to rapidly produce hydrogen directly from water.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Sunshine C
authors.initials: SC
authors.lastname: Silver
authors.forename: Jens
authors.initials: J
authors.lastname: Niklas
authors.forename: Pingwu
authors.initials: P
authors.lastname: Du
authors.forename: Oleg G
authors.initials: OG
authors.lastname: Poluektov
authors.forename: David M
authors.initials: DM
authors.lastname: Tiede
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Utschig
mesh_terms: D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry / Q000378:metabolism*; D008027:Light; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000378:metabolism*; D009942:Organometallic Compounds / Q000378:metabolism; D045331:Photosystem I Protein Complex / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D009942:Organometallic Compounds; D045331:Photosystem I Protein Complex; D009532:Nickel; D006859:Hydrogen