Hierarchical NiCo2S4@NiMoO4 nanotube arrays on nickel foam as an advanced bifunctional electrocatalyst for efficient overall water splitting. (20th December 2022)

• Record Type: Journal Article
• Authors: Pan, Zhiyi; Tang, Zheng; Sun, Dan; Zhan, Yongzhong
• Is Part Of: Electrochimica acta. Volume 436(2022)
• Publication Date: 2022-12-20
• Subjects: NiCo2S4@NiMoO4/NF -- Heterostructure -- Nanotube arrays -- Bifunctional electrocatalyst -- Overall water splitting; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.141393
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: A binder-free electrode of NiCo2 S4 nanotube@NiMoO4 nanosheet heterostructure was constructed. NiCo2 S4 @NiMoO4 /NF requires ultralow cell potentials of 1.46, 1.63 and 1.75 V at 10, 50 and 100 mA cm −2 for more than 100 h. The superior catalytic performance is attributed to the hierarchical sheet-on-tube structure and synergistic effects between NiCo2 S4 and NiMoO4 . Abstract: The development of efficient and robust electrocatalysts for overall water splitting (OWS) has a crucial effect on alleviating energy and environmental issues. Herein, an integrated electrode of hierarchical NiCo2 S4 nanotube@NiMoO4 nanosheet arrays on nickel foam (NiCo2 S4 @NiMoO4 /NF) is constructed via hydrothermal reaction. And the heterostructure can form the strong electron interaction and synergistic effect between NiCo2 S4 and NiMoO4 . Therefore, the NiCo2 S4 @NiMoO4 /NF electrode exhibits prominent electrocatalytic performances with low overpotentials for oxygen and hydrogen evolution reaction (OER: 285 mV; HER: 197 mV) at the current density of 100 mA cm −2 . Moreover, low potentials of 1.46, 1.63, and 1.75 V are needed to reach 10, 50, and 100 mA cm −2 and outstanding stability of 100 h is exhibited using NiCo2 S4 @NiMoO4 /NF as a bifunctional electrocatalyst for OWS, which is superior over most of previously reported cobalt- and nickel-based electrocatalysts. These outstanding performances benefit from the unique hierarchical structure that combines the advantages of the nanosheet/nanotube and binder-free electrode, the specialty of NiCo2 S4 and NiMoO4 in HER and OER, and the protective effect of the NiMoO4, which synergistically enhance the catalytic activity and stability of OWS. Graphical abstract: An integrated electrode of hierarchical NiCo2 S4 nanotube@NiMoO4 nanosheet arrays on nickel foam (NiCo2 S4 @NiMoO4 /NF) was constructed via hydrothermal reaction and acted as efficient and stable bifunctional electrocatalyst for overall water splitting. Image, graphical abstract