Three-dimensional macroporous CNT–SnO2 composite monolith for electricity generation and energy storage in microbial fuel cells

Abstract

A facile electrophoretic deposition method was used to prepare a three-dimensional macroporous CNT–SnO₂ monolith as a MFC anode. This 3D CNT–SnO₂ composite presents a clear micro-structure with CNTs inside and amorphous SnO₂ nanoparticles coating the CNT surface, and has both good electricity generation and energy storage in MFCs. Experimental results show that the CNT–SnO₂ composite possesses good biocompatibility and improved electrical conductivity. Compared with CNT, CNT–SnO₂ presents a much higher output current density (2.21 versus 0.47 mA cm⁻²) and power density (673.5 versus 443.1 mW m⁻²). The discharge–charge experiments show that the CNT–SnO₂ composite has a greater specific capacitance than the CNT electrode (382 versus 42.8 mF cm⁻²) with a discharge–charge current density of 1 mA cm⁻². These results reveal that the 3D CNT–SnO₂ composite has great promise as the anode material for MFCs.