Co, Fe codoped holey carbon nanosheets as bifunctional oxygen electrocatalysts for rechargeable Zn–air batteries

Abstract

CoFe@HNSs exhibited bifunctional oxygen electrocatalytic activity, and exhibit a high-power density of 131.3 mW cm−2 and long-term stability over 140 h.

Synthesis of Tangled Iron‐Nitrogen Co‐doped Carbon Nanosheets through a Dopamine Coordination Strategy for the Oxygen Reduction Reaction

“…The high specific surface area will undoubtedly favor the exposure of more active sites and facilitate the mass transfer in the catalytic reactions. [36][37][38] The pore size distribution analysis (inset in Figure 2c) showed that the micropores (centered at 0.7 nm) and a small amount of mesopores and macropores coexist in FeÀ NÀ C/700 with a total pore volume up to 0.55 cm 3 g À 1 , proving the highly porous structures of the FeÀ NÀ C nanosheets. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface chemical composition and elemental bonding configuration of the samples.…”

“…As shown in Table S1, the specific surface areas of Fe−N−C/700‐Pre and Fe−N−C/700 were as high as 1087.8 and 952.6 m 2 g −1 . The high specific surface area will undoubtedly favor the exposure of more active sites and facilitate the mass transfer in the catalytic reactions [36–38] . The pore size distribution analysis (inset in Figure 2c) showed that the micropores (centered at 0.7 nm) and a small amount of mesopores and macropores coexist in Fe−N−C/700 with a total pore volume up to 0.55 cm 3 g −1 , proving the highly porous structures of the Fe−N−C nanosheets.…”

High‐Performance Zinc‐Air Batteries Based on Bifunctional Hierarchically Porous Nitrogen‐Doped Carbon

“…The fitted N 1s XPS peak is deconvoluted into four peaks referring to pyridinic N (398.2 eV), pyrrolic N (399.5 eV), graphitic N (401 eV), and oxidized N (402.5 eV), respectively (Figure 2b, Figure S6, Supporting Information). [ 29 ] As shown in Figure 2c, DAP‐HPNC‐1020 possesses a higher N content (4.12 wt%) than those of oPD‐HPNC‐1020 (1.85 wt%) and mPD‐HPNC‐1020 (3.62 wt%), which may be reasoned by the distinct composition of DAP in contrast with those of o‐Phenylenediamine (oPD) and m‐Phenylenediamine (mPD). 4.12 wt% of N content is a pretty high level in contrast with other reported N‐doped catalysts, the normal N content of which is around 2–4 wt%.…”

Achieving efficient oxygen reduction on ultra-low metal-loaded electrocatalysts by constructing well-dispersed bimetallic sites and interconnected porous channels

“…22 Despite signicant progress having been obtained in FeCo-based TMNC materials for the ORR by modulating composition and enlarging surface area, their mass activity is extremely low as the active sites are oen encapsulated within the carbon matrix during the pyrolysis process. Even though atomically dispersed Fe-N x /C and Co-N x /C moieties have sparked wide research interest recently in view of the maximized atomic efficiency, [24][25][26][27] the tedious preparation methods oen give rise to uneven metal distribution and aggregation. Considering that the ORR is a tri-phase (gas/liquid/ solid) process, hierarchically porous architectures with interconnected macro-/microchannels are essential for guaranteeing accessibility of active sites and accelerating mass transfer.…”