Revealing Co‐N<sub>4</sub>@Co‐NP Bridge‐Enabled Fast Charge Transfer and Active Intracellular Methanogenesis in Bio‐Electrochemical CO<sub>2</sub>‐Conversion with <i>Methanosarcina Barkeri</i>
Rongxin Xia, Jun Cheng, Zhuo Chen, Ze Zhang, Xinyi Zhou, Junhu Zhou, Meng Zhang
Abstract
Abstract To significantly advance the bio‐electrochemical CO 2 ‐conversion rate and unfold the correlation between the abiotic electrode and the attached microorganisms, an atomic‐nanoparticle bridge of Co‐N 4 @Co‐NP crafted in metal–organic frameworks‐derived nanosheets is integrated with a model methanogen of Methanosarcina barkeri ( M. barkeri ). The direct bonding of N in Co‐N 4 and Fe in member protein of Cytochrome b (Cytb) activates a fast direct electron transfer path while the Co nanoparticles further strengthen this bonding via decreasing the energy gap between the p‐band center of N and the d‐band center of Fe. This multiorbital tuning operation of Co nanoparticles also enhances the coenzyme F420 ‐mediated electron transfer by enabling the electron flow direct to the hydrogenation sites. Particularly, the increased surface electric field of the Co‐N 4 @Co‐NP bridge‐based nanosheet electrode facilitates the interfacial Na + accumulation to expedite ATPase transport for powering intracellular CO 2 conversion. Remarkably, the self‐assembled M.barkeri ‐Co‐N 4 @Co‐NP biohybrid achieves a high methane production rate of 3860 mmol m −2 day −1 , which greatly outperforms other reported biohybrid systems. This work demonstrates a comprehensive scrutinization of biotic–abiotic energy transfer, which may serve as a guiding principle for efficient bio‐electrochemical system design.