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 CO 2 into chemicals. In this technique, electrons are acquired either directly or indirectly through H 2 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 H 2 production rate with the conductive bio-abiotic composite was 41.51 ± 2.54 × 102 mol d−1, while the undecorated carbon felt was 12.96 ± 1.09 × 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. [ABSTRACT FROM AUTHOR]