TY - JOUR
T1 - One-Pot Synthesis of NiCo2S4 Hollow Spheres via Sequential Ion-Exchange as an Enhanced Oxygen Bifunctional Electrocatalyst in Alkaline Solution
AU - Feng, Xueting
AU - Jiao, Qingze
AU - Cui, Huiru
AU - Yin, Mengmeng
AU - Li, Qun
AU - Zhao, Yun
AU - Li, Hansheng
AU - Zhou, Wei
AU - Feng, Caihong
N1 - Publisher Copyright:
Copyright © 2018 American Chemical Society.
PY - 2018/9/5
Y1 - 2018/9/5
N2 - The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are considered to be cornerstones of many energy conversion and storage technologies. It is difficult studying high-performance nonprecious materials as cost-effective bifunctional electrocatalysts for both the OER and ORR in future practical applications. In this study, NiCo2S4 hollow spheres (NiCo2S4 HSs) were fabricated via an effective and facile one-pot "green" approach in an N,N-dimethylformamide-ethylene glycol binary solution. The obtained NiCo2S4 HSs had a high specific surface area as well as numerous active sites and showed a remarkable catalytic performance and durability toward both the OER and ORR in an alkaline electrolyte. For the ORR, NiCo2S4 HSs exhibited a positive half-wave potential of 0.80 V and demonstrated outstanding stability and enhanced methanol tolerance. For the OER, NiCo2S4 HSs presented a low overpotential (400 mV) at a current density of 10 mA cm-2, small Tafel slope, and excellent stability in 0.1 M KOH. Moreover, regarding the overall electrocatalytic activity, the potential difference of NiCo2S4 HSs was 0.83 V, surpassing that of NiCo2S4 nanoparticles, binary counterparts (CoS, NiS), and most highly active bifunctional catalysts described in the literature. The superior catalytic performance of NiCo2S4 HSs is mainly ascribed to its unique hollow structure, which increases molecular diffusion and adsorption, as well as the synergistic effect of Ni and Co, which offers richer redox reaction sites. Importantly, this strategy may facilitate the design and preparation of excellent bifunctional nonprecious metal electrocatalysts in various domains.
AB - The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are considered to be cornerstones of many energy conversion and storage technologies. It is difficult studying high-performance nonprecious materials as cost-effective bifunctional electrocatalysts for both the OER and ORR in future practical applications. In this study, NiCo2S4 hollow spheres (NiCo2S4 HSs) were fabricated via an effective and facile one-pot "green" approach in an N,N-dimethylformamide-ethylene glycol binary solution. The obtained NiCo2S4 HSs had a high specific surface area as well as numerous active sites and showed a remarkable catalytic performance and durability toward both the OER and ORR in an alkaline electrolyte. For the ORR, NiCo2S4 HSs exhibited a positive half-wave potential of 0.80 V and demonstrated outstanding stability and enhanced methanol tolerance. For the OER, NiCo2S4 HSs presented a low overpotential (400 mV) at a current density of 10 mA cm-2, small Tafel slope, and excellent stability in 0.1 M KOH. Moreover, regarding the overall electrocatalytic activity, the potential difference of NiCo2S4 HSs was 0.83 V, surpassing that of NiCo2S4 nanoparticles, binary counterparts (CoS, NiS), and most highly active bifunctional catalysts described in the literature. The superior catalytic performance of NiCo2S4 HSs is mainly ascribed to its unique hollow structure, which increases molecular diffusion and adsorption, as well as the synergistic effect of Ni and Co, which offers richer redox reaction sites. Importantly, this strategy may facilitate the design and preparation of excellent bifunctional nonprecious metal electrocatalysts in various domains.
KW - NiCoS HSs
KW - alkaline electrolyte
KW - nonprecious metal electrocatalysts
KW - oxygen evolution reaction
KW - oxygen reduction reaction
UR - http://www.scopus.com/inward/record.url?scp=85052326313&partnerID=8YFLogxK
U2 - 10.1021/acsami.8b08547
DO - 10.1021/acsami.8b08547
M3 - Article
C2 - 30102862
AN - SCOPUS:85052326313
SN - 1944-8244
VL - 10
SP - 29521
EP - 29531
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 35
ER -