Fabrication of 3D heteroatom-doped porous carbons from self-assembly of chelate foams via a solid state method

Abstract

Novel three-dimensional (3D) foam-like porous carbon architectures with homogeneous N doping and unique mesopore-in-macropore structures have been fabricated from a metal–organic complex via a simple template-free solid state method, which have a high specific surface area (2732 m² g⁻¹), large pore volume (3.31 cm³ g⁻¹), interconnected hierarchical pore structures with macro/meso/micro multimodal distribution and abundant surface functionality N doping (5.36 wt%). These characteristics give high catalytic performance for oxygen reduction with an onset potential of 0.98 V [versus reversible hydrogen electrode (RHE)] and a half-wave potential of 0.83 V (versus RHE) in alkaline media, which are comparable with those of the state-of-the-art platinum/carbon catalyst and many noble metal free catalysts. These results demonstrate the significant advantages of the unique mesopore-in-macropore porous structures with efficient heteroatom doping, which provides abundant accessible active sites for high mass and charge transports. The present work provides a new, simple and environmentally safe synthesis strategy for the preparation of 3D porous carbon architectures for use as efficient electrochemical energy devices and gives good insight into the fabrication of advanced nanostructured materials.