Metal nitrides have attracted significant attention due to their noble metal-like electron features; however, their applications are still limited by numerous predicaments in their synthesis owing to their large bond enthalpy and high ionization potential, which is generally implemented under extra-high pressure and temperature. Herein, the controllable synthesis of CoN3 nanoparticles embedded in graphite carbon was successfully achieved through the in situ pyrolysis of a Co/Zn-ZIF-67 (ZIF, zeolitic imidazolate framework) precursor (Co/Zn molar ratio ranging from 5/95 to 9/91 in Zn-ZIF-67 crystals). During the pyrolysis, the Co/Zn-ZIF-67 precursor was first converted into Co nanoparticles (NPs) embedded in N-doped porous carbon (Co@NC), accompanied by the release of NH3 from the decomposition of the ZIF structure. The abundant micropores formed by the evaporation of Zn and large surface area of Co@NC facilitate the contact between NH3 molecules and Co, generating CoN3 species. Importantly, when the CoN3@NC-7-1000 sample was evaluated as an electrocatalyst for the oxygen reduction reaction (ORR), it exhibited high performance with a positive half-wave potential (0.72 V vs. RHE) and a high current density (5.40 mA cm-2) in the 0.5 M H2SO4 electrolyte. According to the density functional theory (DFT) calculation, the exposed (220) facet of CoN3 with a low energy barrier can benefit the adsorption of O2 molecules.
|Number of pages||8|
|Journal||Journal of Materials Chemistry A|
|Publication status||Published - 2019|
Bibliographical noteFunding Information:
We are grateful for the nancial support by the National Natural Science Foundation of China (grant no. 21501105, 51808303 and 51672143), Taishan Scholars Program, Taishan Scholar Foundation (ts201511019), the Applied Basic Research of Qingdao City (Special Youth Project) (no. 19-6-2-74-cg) and Outstanding Youth of Natural Science in Shandong Province (JQ201713).
© 2019 The Royal Society of Chemistry.
Copyright 2019 Elsevier B.V., All rights reserved.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)