CoP-Fe2O3/g-C3N4 photocathode enhances the microbial electrosynthesis of polyhydroxybutyrate production via CO2 reduction
Kang Zhang, Xingchao Xu, Xiang Ling Li, Tian‐shun Song, Jingjing Xie, Ting Guo
Abstract
The hydrogen energy and CO 2 reduction in-situ recombination has drawn increasing attention. Microbial electrosynthesis (MES) integrated with photocatalytic materials is a novel technology for CO 2 utilization. Here, MES with the photocathode CoP-Fe 2 O 3 /g-C 3 N 4 was constructed using Ralstonia eutropha as biocatalyst to generate polyhydroxybutyrate (PHB). The integration of CoP and Fe 2 O 3 /g-C 3 N 4 facilitated electron–hole pair separation and electron transfer, which enhanced hydrogen evolution reaction and provided additional reducing power for CO 2 conversion. Simultaneously, the concentration of reactive oxygen species was also considerably reduced, increasing the production of PHB. In particular, 87.54 mg/L of PHB was obtained in CoP-Fe 2 O 3 /g-C 3 N 4 at − 1.05 V, which is about three times higher than that in carbon felt. At − 0.9 V, PHB concentration further increased to 142.20 mg/L. This study provides a new approach for converting CO 2 into multicarbon compounds in situ electrolysis of water under visible light.