α-Fe<sub>2</sub>O<sub>3</sub>/g-C<sub>3</sub>N<sub>4</sub> Z-Scheme Heterojunction Photocathode to Enhance Microbial Electrosynthesis of Acetate from CO<sub>2</sub>
Tao Li, Kang Zhang, Tian‐shun Song, Jingjing Xie
Abstract
A visible-light responsive photocathode microbial electrosynthesis (MES) is an attractive method for CO2 fixation via a microbial electrochemical process. Here, an α-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 α-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 α-Fe2O3 can promote electron transfer between the electrode and microorganisms. α-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.