In:
Electrochemical Science Advances, Wiley, Vol. 2, No. 2 ( 2022-04)
Abstract:
Developing highly effective and stable non‐precious bifunctional oxygen electrocatalysts is crucial and challenging. Herein, we report nano‐mediated straight bamboo‐shaped nitrogen‐doped carbon nanotubes modified with encapsulated NiCo 2 S 4 ‐based nanoparticles (E‐NiCo 2 S 4 /SBS‐NCNTs) by electrodeposition and procedural calcination strategy, in which nitrogen‐doped carbon nanotubes with straight bamboo shape (SBS‐NCNTs) show more average diameter and encapsulated NiCo 2 S 4 ‐based nanoparticles (E‐NiCo 2 S 4 ) are coated by carbon, and what makes us even more excited is that they are evenly dispersed on SBS‐NCNTs surface, not just at the tip or inside. When applied for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), E‐NiCo 2 S 4 /SBS‐NCNTs show excellent catalytic activity, and onset potential (E onset ) in OER and ORR is only 1.52 V and 0.95 V (vs. RHE) in 0.1 M KOH, respectively. More importantly, the hybrids exhibit good methanol tolerance, with almost unchanged for ORR performance after adding 0.5 M methanol, and it has highly stability, the current density dropped by 22% after 7 h of reaction. The interaction of NiCo 2 S 4 with the external carbon layer can greatly enhance the electrocatalytic activity toward the OER and it has a complete 4e – reaction process toward the ORR. The excellent electrocatalytic activity is mainly due to synergistic enhancement effect, in which SBS‐NCNTs with highly catalytic activity provide good conductivity, expose more active sites and promotes fast mass transfer; Carbon‐coated NiCo 2 S 4 ‐based nanoparticles can improve the local work function of SBS‐NCNT through synergistic electronic interaction, promoting O 2 adsorption, ensure rapid electron transport, and enable SBS‐NCNT to improve its electrocatalytic activity. Because of the weakness of Ostwald effect and synergistic enhancement, the stability and catalytic activity of NiCo 2 S 4 ‐based nanoparticles can be greatly improved. All these advantages can synergistically improve the electrocatalytic efficiency and make it become one of the most promising bifunctional oxygen electrocatalysts.
Type of Medium:
Online Resource
ISSN:
2698-5977
,
2698-5977
DOI:
10.1002/elsa.202100034
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
2984616-X
Permalink