A Ternary Ni46 Co40 Fe14 Nanoalloy-Based Oxygen Electrocatalyst for Highly Efficient Rechargeable Zinc-Air Batteries.
Gyutae NamYeonguk SonSung O ParkWoo Cheol JeonHaeseong JangJoohyuk ParkSujong ChaeYoungshin YooJaechan RyuMin Gyu KimSang Kyu KwakJaephil ChoPublished in: Advanced materials (Deerfield Beach, Fla.) (2018)
Replacing noble-metal-based oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts is the key to developing efficient Zn-air batteries (ZABs). Here, a homogeneous ternary Ni46 Co40 Fe14 nanoalloy with a size distribution of 30-60 nm dispersed in a carbon matrix (denoted as C@NCF-900) as a highly efficient bifunctional electrocatalyst produced via supercritical reaction and subsequent heat treatment at 900 °C is reported. Among all the transition-metal-based electrocatalysts, the C@NCF-900 exhibits the highest ORR performance in terms of half-wave potential (0.93 V) in 0.1 m KOH. Moreover, C@NCF-900 exhibits negligible activity decay after 10 000 voltage cycles with minor reduction (0.006 V). In ZABs, C@NCF-900 outperforms the mixture of Pt/C 20 wt% and IrO2 , cycled over 100 h under 58% depth of discharge condition. Furthermore, density functional theory (DFT) calculations and in situ X-ray absorption spectroscopy strongly support the active sites and site-selective reaction as a plausible ORR/OER mechanism of C@NCF-900.
Keyphrases
- highly efficient
- density functional theory
- transition metal
- metal organic framework
- molecular dynamics
- high resolution
- solid state
- electron transfer
- photodynamic therapy
- reduced graphene oxide
- heavy metals
- optical coherence tomography
- magnetic resonance imaging
- risk assessment
- heat stress
- combination therapy
- mass spectrometry
- molecular docking
- gold nanoparticles
- computed tomography
- replacement therapy