Enhanced electrocatalytic oxygen evolution reaction kinetics using dual-phase engineering of self-supported hierarchical NiCoV(OH)x nanowire arrays. (15th November 2021)

• Record Type: Journal Article
• Authors: Ansari, Mohammad Shaad; Kim, Haekyoung
• Is Part Of: Fuel. Volume 304(2021)
• Publication Date: 2021-11-15
• Subjects: Self-supported -- Hierarchical nanowires array -- Electrocatalytic oxygen evolution -- Overpotential -- Charge transfer resistance; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.121309
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: Self-supported hierarchical trimetallic NiCoV(OH)2 nanowire arrays-based electrocatalyst. Low overpotential (~320 mV at a 50 mA/cm 2 ) and Tafel slope (~114 mV/dec) for OER. Smaller charge transfer resistance (Rct ; ~ 0.63 Ω) and a larger Cdl (~77 mF/cm 2 ) Higher catalytic active sites, high conductivity and faster charge transfer kinetics. Remarkable electrochemical stability at a high current density of 50 mA/cm 2 for 10 h. Abstract: Transition multi-metal components with high oxidation states can expedite the slow oxygen evolution reaction (OER) kinetics owing to their high intrinsic catalytic activity. Herein, we propose dual-phase engineering of self-supported hierarchical trimetallic NiCoV double hydroxides (NiCoV(OH)x ) nanowire arrays for enhanced electrocatalytic OER activity via increased surface reaction sites and charge transfer. X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy analyses are performed to demonstrate the chemical composition and structural features of the synthesized electrocatalysts. Self-supported NiCoV(OH)x shows better OER catalytic performance with an overpotential of ~ 320 mV at a current density of 50 mA/cm 2 and Tafel slope (~114 mV/dec) in 1 M KOH electrolyte medium. Furthermore, NiCoV(OH)x exhibits a smaller charge transfer resistance (Rct; ~ 0.63 Ω) and a larger Cdl value (~77 mF/cm 2 ) than NiCo(OH)x (~1.22 Ω, 53 mF/cm 2 ) and NiV(OH)x (~1.86 Ω, 46 mF/cm 2 ), suggesting faster electrocatalytic kinetics. NiCoV(OH)x displays remarkable electrochemical stability at a high current density of 50 mA/cm 2 for 10 h without significant changes in the OER activity. Owing to its greater abundance of catalytic active sites, high conductivity, faster charge transfer kinetics, and close contact with the electrolyte, NiCoV(OH)x exhibits superior electrocatalytic performance and stability toward the OER.