Hydrogen-Mediated Electron Transfer in Hybrid Microbial-Inorganic Systems and Application in Energy and the Environment

The conversion of electrical energy to chemical energy is a promising approach to store and utilize renewable electricity. Hybrid microbial-inorganic systems incorporating abiotic catalysts with biocatalysts have been proved to efficiently achieve this conversion. To couple electrocatalytic reactions with microorganism metabolism, H-2 can be an ideal mediator for energy and electron transfer between electrodes and microorganisms. In hydrogen-mediated hybrid microbial-inorganic systems, H-2 is produced at the cathodes with abiotic hydrogen evolution reaction catalysts. H-2 then functions as an energy carrier and electron donor for hydrogen-oxidizing microorganisms. Hybrid microbial-inorganic systems have been prevalently used for energy and environmental applications. Herein, the principle, applications, and current challenges of the hybrid microbial-inorganic systems are summarized.