N-doped Fe nanoparticles anchored on 3D carbonized sugarcane anode for high power density and efficient chromium(VI) removal

Microbial fuel cells (MFCs) are attractive due to the inherent potential for effective clean energy extraction from wastewater. Unfortunately, it is still a challenge to achieve high power by improving the extracellular electron transfer (EET) efficiency between the bacteria and the electrode. Herein, a three-dimensional (3D) macroporous sugarcane carbon (SC) embedded with Fe nanoparticles (20-40 nm) with graphite protective layers (3D nano-Fe@C/SC) is prepared for the MFC anode. The 3D nano-Fe@C/SC anode with low charge transfer resistance (0.38 Omega) facilitates microbial adhesion/colonization, achieving a superior power density of 3012.7 mW m(-2) in acetate-feeding MFC, which is higher than that of previously reported studies dealing with biochar-based anodes. The 3D nano-Fe@C/SC anode also exhibits a higher Cr(VI) removal efficiency (91 %) than that of SC (63 %) or carbon cloth (CC) (16 %) anodes under neutral conditions (pH 6.7). This high-performance anode material can promote pollutant removal and energy conversion, which will have promising applications in sustainable wastewater treatment via MFCs.

Automated summary

In this study, a three-dimensional macroporous sugarcane carbon material embedded with iron nanoparticles was prepared as an anode material for microbial fuel cells (MFCs). The resulting anode showed low charge transfer resistance and superior power density, as well as higher pollutant removal efficiency under neutral conditions.