Self-supported microbial carbon aerogel bioelectrocatalytic anode promoting extracellular electron transfer for efficient hydrogen evolution

Abstract

Hydrogen production by microbial electrolysis cells (MECs) is an attractive and promising technology for sustainable energy. The bioelectrocatalytic activity of bioanode plays an essential role in improving the supply of electrons to cathode. Herein, a self-supported three-dimensional (3D) porous carbon aerogel (CA) bioanode was successfully applied in a MEC system for efficient hydrogen production. The 3D porous structure of CA greatly increased the bacterial incubation, then favored the extracellular electron transfer (EET) owing to its high specific surface area, excellent electrical conductivity and enhanced interaction with microbial. As a result, the hydrogen production of Bio-CA||Pt (0.37 μmol cm−2 h−1) was 5 times higher than that of bio-carbon fiber (Bio-CF)||Pt (0.007 μmol cm−2·h−1) at the bias voltage of 0.3 V. Such a MEC with self-supported 3D porous microbial CA bioanode as a promising biotechnology will be further investigated for pollutant degradation and hydrogen production.