In Situ Formed Edge-Rich Ni3S2-NiOOH Heterojunctions for Oxygen Evolution Reaction. Issue 5 (1st May 2022)

• Record Type: Journal Article
• Authors: Yan, Qing; Liu, Zheng; Bai, Xiaojing; Zhang, Xuan; Gao, Ruiqin; Yuan, Weiyong; Chen, Zhengfei; Li, Zhoupeng; Li, Yiju
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 5(2022)
• Publication Date: 2022-05-01
• Subjects: Edge-Rich -- Freestanding -- Ni3S2-NiOOH Heterojunction Structure -- Oxygen Evolution Reaction; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac7083
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Developing highly active, earth-abundant, and durable electrocatalysts is desired but challenging for oxygen evolution reaction (OER). In this work, we design an electrocatalyst of the edge-rich nickel sulfide arrays on the nickel foam (Ni3 S2 NSs-NF) by a facile yet efficient wet-chemical method. Benefiting from the three-dimensional nanostructure with numerous active edges, the prepared Ni3 S2 NSs-NF exhibits superior OER performance in alkaline conditions. An in-depth study reveals that the real active sites toward OER are the in situ formed heterogenous Ni3 S2 -NiOOH. Density functional theory (DFT) calculations indicate the density of state (DOS) of the Ni3 S2 -NiOOH heterojunction near the Fermi level is enhanced, contributing to higher electronic conductivity. As a result, the Ni3 S2 NSs-NF with abundant Ni3 S2 -NiOOH heterojunctions exhibits an efficient electrochemical activity toward OER in alkaline conditions. The Ni3 S2 NSs-NF electrode shows an overpotential of 244 mV at 10 mA cm −2 with a Tafel slope of 75 mV dec −1 and possesses ultrastable performance even at 100 mA cm −2 .