title: Cysteine-Cystine Photoregeneration for Oxygenic Photosynthesis of Acetic Acid from CO2 by a Tandem Inorganic-Biological Hybrid System.
abstract: Tandem "Z-scheme" approaches to solar-to-chemical production afford the ability to independently develop and optimize reductive photocatalysts for CO2 reduction to multicarbon compounds and oxidative photocatalysts for O2 evolution. To connect the two redox processes, molecular redox shuttles, reminiscent of biological electron transfer, offer an additional level of facile chemical tunability that eliminates the need for solid-state semiconductor junction engineering. In this work, we report a tandem inorganic-biological hybrid system capable of oxygenic photosynthesis of acetic acid from CO2. The photoreductive catalyst consists of the bacterium Moorella thermoacetica self-photosensitized with CdS nanoparticles at the expense of the thiol amino acid cysteine (Cys) oxidation to the disulfide form cystine (CySS). To regenerate the CySS/Cys redox shuttle, the photooxidative catalyst, TiO2 loaded with cocatalyst Mn(II) phthalocyanine (MnPc), couples water oxidation to CySS reduction. The combined system M. thermoacetica-CdS + TiO2-MnPc demonstrates a potential biomimetic approach to complete oxygenic solar-to-chemical production.
authors.affiliation: Department of Chemistry, University of California-Berkeley , Berkeley, California 94702, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94702, United States.
authors.forename: Kelsey K
authors.initials: KK
authors.lastname: Sakimoto
authors.affiliation: Department of Chemistry, University of California-Berkeley , Berkeley, California 94702, United States.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of California-Berkeley , Berkeley, California 94702, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94702, United States.|Kavli Energy NanoSciences Institute , Berkeley, California 94702, United States.
authors.forename: Peidong
authors.initials: P
authors.lastname: Yang
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D003553:Cystine / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen; D010788:Photosynthesis
chemical_list: D002245:Carbon Dioxide; D003553:Cystine; D003545:Cysteine; D019342:Acetic Acid; D010100:Oxygen
keywords: Cadmium sulfide; Moorella thermoacetica; artificial photosynthesis; phthalocyanine; solar-to-chemical production; titanium dioxide