Research on the electrocatalytic reduction of CO2 by microorganisms with a nano-titanium carburizing electrode

The reduction of CO2 to organics using microbial electrosynthesis (MES) is currently a popular research direction in the environmental field. In this study, we evaluated the effect of the electrode material on the production of organics from CO2 in microbial electrosynthesis with a mixed-culture biocathode. The electrode material is an important factor influencing electron transfer, since it directly affects the efficiency of CO2 reduction. In this study, we compared the performance of a graphite electrode and a metal-based carbon hybrid material electrode for the electro-reduction of CO2. The cathode potential was set to -0.8 V (vs Ag/AgCl). When the cathode material was changed from a graphite electrode to a nano-titanium carburizing electrode, the current density of MES increased from 1.66 +/- 0.2 A.m(-2) to 2.75 +/- 0.2 A.m(-2), acetate accumulation increased from 127 mg/L to 234 mg/L, butyrate accumulation increased from 46 mg/L to 86.5 mg/L, and the total electron recovery of MES increased to nearly 70%. The results show that improving electrode performance can effectively improve the efficiency of MES for reducing CO2. Metal-based carbon hybrid materials have good biological affinity and stability and also have good electrochemical performance. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study demonstrates that improving electrode performance can effectively enhance the efficiency of microbial electrosynthesis for CO2 reduction. Metal-based carbon hybrid materials show promise due to their good biological affinity, stability, and electrochemical performance.