Cross-linked Polypyrrole@Co3O4 for boosting bioenergy output and regulating electroactive microflora in sediment microbial fuel cells

Sediment microbial fuel cell (SMFC) has been regarded as a promising device for simultaneously bioenergy supply and bioremediation, but the low power density and less research on bioremediation still hinders its practical application. As the carrier of exoelectrogens, anode is closely related to above characteristics of SMFC. Thus, the modification of anode is a reliable way to improve SMFC performance. In this paper, the graphite plate (GP) is modified with polypyrrole/Co3O4 composite (PPy@Co3O4) by electrodeposition to obtain a high capacitive and conductive electrode. SMFC equipped with PPy@Co3O4-GP shows maximum power density of 247.89 mW/m2, nearly 1.94 times higher than blank control group (127.61 mW/m2). The microflora analysis exhibits that PPy@Co3O4-GP has great screening ability for electroactive microbes, and forming electroactive functional microflora involved with Sulfurovum and Streptococcus. The results of sediment composition show that PPy@Co3O4-GP has good bioremediation potential. This work provides an easy and reliable surface modification method for the development of high-performance bioenergy harvesting and bioremediation SMFC anodic materials. •A three-dimensional cross-linked structure PPy@Co3O4-GP as anode of sediment microbial fuel cell.•PPy@Co3O4-GP exhibits high capacitance and conductivity.•PPy@Co3O4-GP can enhance the power generation performance for sediment microbial fuel cell.•PPy and Co3O4 composite modification facilitates the formation and functional differentiation of electroactive communities for bioanode.•PPy@Co3O4-SMFC demonstrates good bioremediation potential in sediment environment.