Three dimension Ni/Co-decorated N-doped hierarchically porous carbon derived from metal-organic frameworks as trifunctional catalysts for Zn-air battery and microbial fuel cells

Development of noble metal-free catalysts with great electrocatalytic performance and stability is of importance for electrochemical energy conversion and storage devices. Herein, we reported the synthesis of trifunctional catalysts with three-dimension (3D) hierarchically porous nitrogen-doped carbon framework with Ni-Co dual metal-involving and carbon nanotubes growth derived from nickel metal-organic framework. The as-synthesized catalyst exhibited better oxygen reduction reaction performance under both neutral and basic conditions compared with commercial Pt/C catalysts. Under basic electrolyte, the oxygen evolution reaction performance of the synthesized catalyst was comparable to that of commercial IrO 2 catalysts and reasonable hydrogen evolution activity was achieved compared with reported non-noble metal-based catalysts. The assembled microbial fuel cell using the as-prepared material as the air electrode exhibited a maximum power density of 1971.2 mW m −2 and could steadily operate for more than 250 h of feed period. Furthermore, the Zn-air battery fabricated with the obtained catalyst showed excellent power density and rechargeability, which were superior to that of a Zn-air battery using Pt/C/IrO 2 as the air electrode. We anticipate that the results described here can provide a new idea for design of multifunctional electrocatalysts for energy conversion and storage devices.