Light augmented CO2 conversion by metal organic framework sensitized electroactive microbes

Abstract Recently, photosynthetic biohybrid systems are emerged as efficient catalytic materials having advantages of the light-harvesting ability of semiconductors and the catalytic efficiency of biological system. In this context, a stable visible light active Zn-metal organic framework (ZTC) functionalized with TiO2 (ZTC@TiO2) was synthesized, and synergistically integrated with an electroactive microbial (EAB) system for efficient CO2 reduction under visible-light illumination. The resultant bio-hybrid shows remarkably higher CO2 reduction under visible light irradiation as compared to independent ZTC@TiO2 and microbe system. Under optimized condition, the bioinorganic hybrid (EAB-ZTC@TiO2) shows a CO2 conversion to acetic acid and methanol with a higher selectivity towards methanol. The improved photocatalytic CO2 conversion and selectivity towards methanol is ascribed to a well-organized donor-acceptor interfacial charge transfer from ZTC@TiO2 to a microbe, which effectively activates the Wood-Ljungdahl pathway of microbes, thereby improving the CO2 reduction efficiency.