Abstract
Both artificial photosystems and natural photosynthesis have not reached their full potential for the sustainable conversion of solar energy into specific chemicals. A promising approach is hybrid photosynthesis combining efficient, non-toxic, and low-cost abiotic photocatalysts capable of water splitting with metabolically versatile non-photosynthetic microbes. Here, we report the development of a water-splitting enzymatic photocatalyst made of graphitic carbon nitride (g-C(3)N(4)) coupled with H(2)O(2)-degrading catalase and its utilization for hybrid photosynthesis with the non-photosynthetic bacterium Ralstonia eutropha for bioplastic production. The g-C(3)N(4)-catalase system has an excellent solar-to-hydrogen efficiency of 3.4% with a H(2) evolution rate up to 55.72 μmol h(-1) while evolving O(2) stoichiometrically. The hybrid photosynthesis system built with the water-spitting g-C(3)N(4)-catalase photocatalyst doubles the production of the bioplastic polyhydroxybutyrate by R. eutropha from CO(2) and increases it by 1.84-fold from fructose. These results illustrate how synergy between abiotic non-metallic photocatalyst, enzyme, and bacteria can augment solar-to-multicarbon chemical conversion.