Self-assembly of graphene oxide and Shewanella oneidensis MR-1 formed a conductive bio-abiotic composite for enhancing microbial electrosynthesis performance

Microbial electrosynthesis (MES) is an attractive technology for converting CO2 into chemicals. In this technique, electrons are acquired either directly or indirectly through H2 in the cathode. Shewanella oneidensis MR-1 can perform hydrogen evolution reaction via reverse electron transfer at the cathode. In this study, the self-assembly of graphene oxide and S. oneidensis MR-1 formed a conductive bio-abiotic composite as a cathode for MES with Clostridium ljungdahlii, obtaining more biocatalysts for hydrogen evolution and enhancing electron transfer rate. The average H2 production rate with the conductive bio-abiotic composite was 41.51 +/- 2.54 x 102 mol d-1, while the undecorated carbon felt was 12.96 +/- 1.09 x 102 mol d-1. Consequently, acetate and butyrate yields were 0.18 g L-1 d-1 and 0.07 g L-1 d-1, which increased by 2.1 and 1.7 times those of the control, respectively. This work provides new opportunities for constructing a highly efficient cathode via biotic-abiotic hybrid composite for improving MES performance.

Automated summary

Microbial electrosynthesis (MES) is an attractive technology for converting CO2 into chemicals. It was found in this study that using a conductive bio-abiotic composite as the cathode can enhance the rate and yield of hydrogen evolution reaction.