Berkeley Lab Berkeley Lab A-Z Index Phone Book Jobs Search DOE

Solar Powered Green Energy Using Seqeuestered Carbon Dioxide

Artificial photosynthesis system components: 1) harvesting solar energy; 2) generating reducing equivalents; 3) reducing CO2 to biosynthetic intermediates; 4) producing value-added chemicals.

Scientific Achievement
Created hybrid artificial photosynthesis system of semiconducting nanowires and bacteria that converts CO2 and water into acetate, the most common building block for biosynthesis.

Significance and Impact
The new system can produce chemicals and fuels in an entirely renewable way, putting sequestered CO2 to good use for the synthesis of targeted, value-added chemical products.

Research Details

  • In natural photosynthesis, leaves harvest solar energy to reduce CO2 which is combined with water for the synthesis of molecular products that form biomass
  • In the new artificial system, a ‘forest’ of nanowires harvest solar energy and deliver electrons to a population of S. ovata bacteria which produce enzymes that catalyze reduction of CO2 to form acetate
  • E. coli then synthesize targeted chemical products from the acetate produced by S. ovata
  • A key to success is the separation of requirements for light-capture efficiency and catalytic activity, made possible by the nanowire/bacteria hybrid technology
  • The system achieves solar energy conversion up to 0.38% for 200 hrs under simulated sunlight, efficiency comparable to that of a leaf

C Liu, J Gallagher, K Sakimoto, E Nichols, C Chang, M Chang, & P Yang, Nano Lett 2015.