Graphene-Based Bioreactor for Renewable Energy Generation from Biomass

The high electrical conductivity and low dimensionality of graphene is essential for the development of novel lightweight electrodes for bioenergy technologies with a zero CO2 footprint. However, the integration of graphene in ecosystems presents a formidable challenge, especially because the surface energy of graphene is not compatible with living matter. Here we propose a sustainable chemical control method to balance surface hydrophilicity and conductivity of graphene nanowalls to form a graphene-based lightweight sponge bioreactor. The few-nanometer--thick conductive nanowalls create biocompatible hydrophilic microconfinements to harvest the biomass density of electrogenic Shewanella Oneidensis MR-1. The graphene-based bioreactor shows a stable and rapid bio-current response with a steady-state bio-current density of 135.35 mA·m-2 realized within a few hours. Our novel and sustainable graphene-based material provides a revolutionarily energy opportunity for the establishment of new energy-related graphene industries as well as facilitates many startups.