A graphene modified biocathode for enhancing hydrogen production

Abstract

Biocathodes have shown great promise for developing low-cost cathodes for hydrogen production in microbial electrolysis cells (MEC). To promote the performance of hydrogen production with a biocathode, we constructed a graphene modified biocathode and assessed the performance of the modified biocathode by setting different cathode potentials. The results indicated that it was feasible to promote the current density, electron recovery efficiency (ERE) and hydrogen production rate by a modified biocathode using graphene. At −1.1 V (vs. Ag/AgCl), the hydrogen production rate of the graphene modified biocathode even achieved 2.49 ± 0.23 m³ per m³ per day with 89.12 ± 6.03% of ERE at a current density of 14.07 ± 0.06 A m⁻², which were about 2.83 times, 1.38 times and 2.06 times that of the unmodified biocathode, respectively. The hydrogen production performance of the graphene modified biocathode was close to that of the platinum catalyzed cathode and superior to that of the stainless steel mesh cathode at −1.1 V.