Simultaneous Photo Catalysis of SiC/Fe3O4 Nanoparticles and Photo-fermentation of Rhodopseudomonas sp. nov. Strain A7 for Enhancing Hydrogen Production under Visible Light Irradiation
Abstract
To improve hydrogen production of photo-fermentation, synthetic SiC/Fe3O4 nanoparticles with photocatalytic ability were added into the culture system of Rhodopseudomonas sp. strain A7. Results indicated that the hydrogen production was remarkably enhanced with the addition of 100 mg/L SiC/Fe3O4 nanoparticles. The maximum volume and yield of hydrogen achieved 2474 mL/L-culture and 3.02 mol/mol-acetate, respectively. It was worth noting that photocatalysis and photo-fermentation were first realized simultaneously for hydrogen production with the SiC/Fe3O4 nanoparticles. The mechanism of enhancement for producing hydrogen was also investigated. The bacterial aggregation performance was improved by the added SiC/Fe3O4 nanoparticles. The activity of nitrogenase could be promoted while the activity of uptake hydrogenase could be inhibited. Beyond that, electron transfer behavior had taken place between strain A7 and nanoparticles. The electron transfer rate of the hydrogen production system could be promoted and accelerated by photo-generated electrons from SiC/Fe3O4 nanoparticles. Hence, the hydrogen production ability and conversion efficiency of substrate were enhanced. The photocatalytic combining photo-fermentation is promising way for hydrogen production