The photoelectron transfer between semiconductors and cells is the rate-determining step that controls the solar H2 production of whole-cell inorganic-biohybrid systems (IBSs). Herein, we constructed an IBS by using reduced graphene oxide (RGO) to integrate Shewanella oneidensis MR-1 (SW) cells and Cu2O, which exhibited a 11–38-fold enhancement of photocatalytic H2 production compared with RGO-free IBSs (Cu2O/SW and Cu2O/organic electron mediator/SW). Further analysis revealed that RGO provided multifunctional contributions to H2 production from IBS, that is, sufficient area for IBS supporting, efficient photoelectron collection from Cu2O, and effective electron distribution into the cells. This study offers opportunities for rationally designing electron transfer pathways to achieve high-performance IBSs.

Microbial electrocatalysis systems (MES) provide a cutting‐edge solution to global problems associated with the environment and energy, but practical applications are hindered by the expensive electrode materials. Although stainless steel (SS) has been proposed as a promising inexpensive candidate, poor cell/SS interaction results in a low performance for MES. Here, a new synthetic biology approach was established for reinforcing the cell/SS interaction. Hybridized curli nanofibers fused with a metal‐binding domain were heterogeneously expressed onto the cell surface, which realized efficient cell binding with the SS electrode. Consequently, it enabled a ~420‐fold improvement of the anodic power output and a substantial enhancement of the cathodic Coulombic efficiency (from 0.6 to 4% to over 80%) with an SS electrode. This work demonstrates low‐cost MES with an SS electrode and introduces a new avenue to engineer the cell/electrode interaction, which is promising for future practical applications of MES.