Trace N-doped manganese dioxide cooperated with Ping-pong chrysanthemum-like NiAl-layered double hydroxide on cathode for improving bioelectrochemical performance of microbial fuel cell

Abstract

Trace N-doped manganese dioxide (MnO2) nanoparticles were attached to NiAl-layered double hydroxide (LDH) nano sheets by a simple two-step hydrothermal reaction, and N-MnO2@NiAl-LDH was successfully prepared as cathode catalyst of microbial fuel cell (MFC). N-MnO2@NiAl-LDH was Ping-pong chrysanthemum-like structure formed by overlapping lamellar structures, with spherical MnO2 particles attached on. The unique Ping-pong chrysanthemum-like structure and pore size distribution provided large number of electrochemical active sites. The recombination of trace N and MnO2 reduced the charge transfer resistance, accelerated the electron transfer rate, and N-MnO2@NiAl-LDH showed high oxygen reduction reaction (ORR) capability. The maximum output power density of N-MnO2@NiAl-LDH-MFC was 698 mW/m2, about 4.59 times of NiAl-LDH (152.1 mW/m2). The maximum voltage was about 320 mV, and the stability was good for about 7 d. This would provide technical reference for the utilization of cathode catalyst for fuel cells.