?-Fe2O3/g-C3N4 Z-Scheme Heterojunction Photocathode to Enhance Microbial Electrosynthesis of Acetate from CO2

A visible-light responsive photocathode microbial electrosynthesis (MES) is an attractive method for CO2 fixation via a microbial electrochemical process. Here, an alpha-Fe2O3/g-C3N4 formed a Z-scheme heterojunction structure and exhibits high photogenerated electron-hole separation ability under visible light. The low valence band potential of alpha-Fe2O3 makes binding electrons transferred from the anode easier for photogenerated holes, providing an additional driving force to improve MES performance. Furthermore, the introduction of alpha-Fe2O3 can promote electron transfer between the electrode and micro-organisms. alpha-Fe2O3/g-C3N4 achieved an acetate production rate of 0.33 g L-1 d-1, which increased by 3-fold compared to a carbon felt cathode. This work provides new opportunities for constructing a highly efficient photocathode for MES.

Automated summary

This study investigates a method for CO2 fixation via a visible-light responsive photocathode microbial electrosynthesis (MES). By constructing an alpha-Fe2O3/g-C3N4 heterojunction structure, efficient electron-hole separation under visible light is achieved. The introduction of alpha-Fe2O3 promotes electron transfer and improves acetate production. This work provides new opportunities for constructing a highly efficient photocathode for MES.