Characterization of a Photosynthesis-based Bioelectrochemical Film Fabricated with a Carbon Nanotube Hydrogel
Microbial photo-bioelectrochemical cells (MPCs) generate energy through the photosynthetic process of microorganisms. However, all MPCs developed to date require oxidation-reduction mediators to transport electrons from the photosynthetic cells to the electrodes, due to which the power conversion efficiencies of such MPCs are usually low. In this study, we developed a method to increase the power conversion efficiency of MPCs by immobilizing Chlorella cells with multiwall carbon nanotubes (MWCNTs) using a UV-cured polyethylene glycol diacrylate (PEG-DA) hydrogel film within a microfluidic chamber. We report that the photosynthetic current obtained in our setup is ∼3-fold higher than that in normal Chlorella cells. Chronoamperometric measurements of hydrogel films with different ratios of MWCNTs and Chlorella indicate that more current is produced at higher MWCNT concentrations. Scanning electron micrographs were used to visualize immobilized MWCNTs and Chlorella cells, and energy dispersive spectrometry was used to quantify the carbon content of the hydrogel film. Impedance measurements also indicated that the increased current was due to improved harvesting of photosynthetic energy. The findings of this study would provide novel insights to design systems that use natural renewable energy sources for the production of electricity.
Keywordselectrochemistry measurement hydrogel film microbial photo-bioelectrochemical cells (MPCs) micro-fluidic chamber multiwall carbon nanotube (MWCNT) photosynthesis
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The present research was conducted by the research fund of Dankook University in 2018.