Engineering Hollow Core–Shell N–C@Co/N–C Catalysts with Bits of Ni Doping Used as Efficient Electrocatalysts in Microbial Fuel Cells

Abstract

The sluggish and inefficient oxygen reduction reaction (ORR) of cathode catalysts in microbial fuel cells is widely accepted as the key restriction in implementing their large-scale actual production application. Recently, modification of nitrogen-doping carbon materials with some transition metal species (M–N–C) is expected to be reserve force to substitute commercial noble metal catalysts. However, long-term stability is always unable to solve effectively. We report a simple synthetic approach of metal–organic framework-derived hollow core–shell Co–nitrogen codoping-modified porous carbon catalysts (N–C@Co/N–C–n%Ni), which is introduced by bits of Ni substance, via the template method and vacuum-assisted impregnation method that exhibit similar catalytic activity to commercial Pt/C catalysts. The hollow core–shell H–N–C@Co/N–C–3%Ni catalyst shows excellent ORR performance and stability, which is 96.31% of the initial current after 125 h continuous reaction, and has been capable of yielding a maximum power density of 1.17 ± 0.01 W·m–2 with 2% decrease in 45 days for long-term continuous operation.