Water splitting–biosynthetic system with CO 2 reduction efficiencies exceeding photosynthesis

Artificial photosynthesis steps up Photosynthesis fixes CO 2 from the air by using sunlight. Industrial mimics of photosynthesis seek to convert CO 2 directly into biomass, fuels, or other useful products. Improving on a previous artificial photosynthesis design, Liu et al. combined the hydrogen-oxidizing bacterium Raistonia eutropha with a cobalt-phosphorus water-splitting catalyst. This biocompatible self-healing electrode circumvented the toxicity challenges of previous designs and allowed it to operate aerobically. When combined with solar photovoltaic cells, solar-to-chemical conversion rates should become nearly an order of magnitude more efficient than natural photosynthesis. Science , this issue p. 1210