Block Copolymer Self‐Assembly Guided Synthesis of Mesoporous Carbons with In‐Plane Holey Pores for Efficient Oxygen Reduction Reaction

In this paper, a simple approach, using interfacial self-assembly of block copolymers (BCPs) on self-sacrificial templates, for preparing mesoporous carbons with in-plane holey pores, including nitrogen atom-doped carbon nanosheets and nanoflowers (denoted as NHCSs and NHCFs), is reported. The approach employs sheet- or flower-like layered double hydroxide as the templates, P123 copolymer as the pore-directing agent, and m-phenylenediamine as the carbon source. The holey mesopores may shorten the mass transfer distance in the internal active sites of stacked nanosheets, while the 3D packing mode of nanosheets can reduce pore blockage caused by their tight stacking. Profiting from these structural advantages, acting as electrocatalysts for oxygen reduction reaction (ORR), both NHCSs and NHCFs show excellent catalytic performance better than that of carbon nanosheets without holey pores. Particularly, NHCFs exhibit a high half-wave-potential (0.82 V) and a limiting current density (5.4 mA cm-2 ), close to those of commercial Pt-C catalysts. This study provides valuable clues on building mesoporous materials with in-plane holey pores as well as on the effect of pore structure and stacking mode of 2D materials on their electrocatalytic ORR performance.