Harnessing Endogenous Quinones to Orchestrate Water Dynamics and Electron Transfer at a Self‐Reinforcing Bio‐Abiotic Interface

ABSTRACT The bio‐abiotic interface is the central bottleneck in bioelectrochemical CO 2 conversion, where electron and mass transport are governed by an intricate interplay among the electrode, microbial mediators, and interfacial water. Here we show that endogenous quinone mediators serve two coupled roles: shuttling electrons and reconfiguring the interfacial hydrogen‑bond network. Using a CoP nanoparticle‐decorated carbon nanoforest electrode that actively modulates these mediators, we find that the nanoforest surface lowers the adsorption barrier for quinones, accelerating their redox cycling and reducing overpotential for electron injection. Molecular dynamics simulations further reveal that these quinones disrupt the rigid hydrogen‑bond network, creating a localized free‑water zone that minimizes proton transport resistance. The interplay of this accelerated redox cycling and water restructuring generates a self‐reinforcing synergy, reflected by a ten‐fold drop in charge‑transfer resistance at 2.5 V vs. bare carbon felt and a Faradaic efficiency of 89.8% for acetate. This closed‑loop regulation, where material chemistry programs mediator behavior and mediators orchestrate both water dynamics and electron flux, offers a paradigm for engineering bio‑abiotic interface beyond empirical optimization.