Nonmetallic Abiotic-Biological Hybrid Photocatalyst for Visible Water Splitting and Carbon Dioxide Reduction

• Published in: iScience Vol. 23; no. 1; p. 100784
• Main Authors: Tremblay, Pier-Luc, Xu, Mengying, Chen, Yiming, Zhang, Tian
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24.01.2020; Elsevier
• Subjects: Catalysis; Energy Materials; Microbial Biotechnology; Microbial Biotechnology; Energy Materials; Catalysis
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.100784

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-C3N4) coupled with H2O2-degrading catalase and its utilization for hybrid photosynthesis with the non-photosynthetic bacterium Ralstonia eutropha for bioplastic production. The g-C3N4-catalase system has an excellent solar-to-hydrogen efficiency of 3.4% with a H2 evolution rate up to 55.72 μmol h−1 while evolving O2 stoichiometrically. The hybrid photosynthesis system built with the water-spitting g-C3N4-catalase photocatalyst doubles the production of the bioplastic polyhydroxybutyrate by R. eutropha from CO2 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. [Display omitted] •H2O2-degrading enzymes from R. eutropha enable visible-light water splitting by C3N4•C3N4 coupled with bovine catalase has a solar-to-hydrogen efficiency of 3.4%•C3N4-catalase increases CO2 conversion into bioplastic under light by R. eutropha•Heterotrophic bioplastic production by R. eutropha is also improved by C3N4-catalase Catalysis; Microbial Biotechnology; Energy Materials