Sb-modulated synthesis of novel CoSb alloy nanoparticles anchored on N-doped carbon as oxygen electrocatalysts

Abstract

Abstract Rational modulation and optimization of structural properties plays a significant role in advancing the electrocatalytic performance of electrocatalysts. In this study, we report a novel Sb-modulated strategy to synthesize novel CoSb/NC catalysts comprised of CoSb alloy supported on nitrogen-doped carbon (denoted as CoSb/NC). Apart from alloying with Co to generate CoSb alloys, we demonstrated that the evaporation of Sb could modulate the particle size and pore structure of CoSb/NC. Such modulation has facilitated the formation of micro/meso-porous structure to accelerate the mass/charge transport and increase the accessibility of active sites, resulting in a highest kinetic current density of 22.6\xa0mA\xa0cm−2 at 0.85\xa0V vs. RHE as well as a low Tafel slope of 38\xa0mV dec−1, which even outperforms the state-of-the-art Pt/C. Additionally, CoSb/NC is demonstrated to be electrocatalytic active toward OER with the overpotential to be 430\xa0mV at 10\xa0mA\xa0cm−2. Rechargeable Zn-air battery tests reveal that CoSb/NC possesses competitive performance in terms of charge-discharge ability and stability, suggesting its potential application in renewable energy conversion devices. This work provides a novel approach to modulate the structure of nitrogen-doped carbon based materials as efficient oxygen electrocatalysts.