Cysteine-Cystine Photoregeneration for Oxygenic Photosynthesis of Acetic Acid from CO2 by a Tandem Inorganic-Biological Hybrid System

Nano Lett. 2016 Sep 14;16(9):5883-7. doi: 10.1021/acs.nanolett.6b02740. Epub 2016 Aug 18.

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.

Keywords: Cadmium sulfide; Moorella thermoacetica; artificial photosynthesis; phthalocyanine; solar-to-chemical production; titanium dioxide.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetic Acid / chemistry*
  • Carbon Dioxide / chemistry*
  • Cysteine / chemistry*
  • Cystine / chemistry*
  • Oxidation-Reduction
  • Oxygen
  • Photosynthesis*

Substances

  • Carbon Dioxide
  • Cystine
  • Cysteine
  • Acetic Acid
  • Oxygen