Relationship between pore structure of N-doped 3D porous graphene and electrocatalytic performance of oxygen reduction in zinc-air battery

Nitrogen-doped (N-doped) graphene materials with highly-efficient and low cost have a promising application in fuel cell. Herein, N-doped 3D porous graphene catalyst (H-N-Gr) is successfully obtained by hydrothermal and high temperature pyrolysis. Graphitic carbon nitride (g-C 3 N 4 ) and graphene can assemble intentionally into a stable composite precursor through hydrogen bonding and π - π conjugation in hydrothermal process, which can increase doping of nitrogen atoms without changing graphene structure after heat treatment. The prepared H-N-Gr has great catalytic activity for oxygen reduction reaction (ORR) due to its high specific surface area (470.3 m 2 /g) and the plenty of catalytically active pyridine nitrogen (25.4%) and graphitized nitrogen (37.3%) on the surface. In addition, the prepared H-N-Gr has better catalytic stability and methanol tolerance than commercial platinum-carbon catalysts, and exhibits high power density (202.90 mW/cm 2 ) and rapid rate performance when assembled into zinc-air batteries. This research provides a simple and practical method to prepare a high performance ORR metal-free catalyst.