Tuning bacteria-electrode interfaces to improve bioelectrochemical CO₂ conversion

Bioelectrochemical systems hold promise for the sustainable transformation of carbon dioxide (CO₂) using non-photosynthetic bacteria. Despite the progress made in developing electrodes and microbial platforms, significant challenges persist in optimizing electron transfer across the bio-abiotic interface. In this review, we delve into recent advances in fine-tuning bacteria-electrode interfaces to enhance bioelectrochemical CO₂ conversion and to better understand the electron transfer mechanisms between CO₂-fixing microbes and electrodes. Notable achievements, such as single-atom catalyst design, heterologous expression of Mtr complexes, and multimodal characterization approaches, are discussed. However, electron transfer dynamics for many bacteria-electrode pairings remain incompletely understood, impeding the rational design of biosystems. Looking forward, a synergistic approach involving high-resolution characterization techniques, computational modeling, and targeted engineering of both microbial and electrode components is essential. Achieving finely tuned bio-abiotic interfaces at the molecular level holds the promise to revolutionize these bioelectrochemical platforms. With further optimization, scalable and sustainable CO₂ conversion may become technically and economically viable.