Accelerating water dissociation kinetic in Co9S8 electrocatalyst by mn/N Co-doping toward efficient alkaline hydrogen evolution. (11th February 2021)

• Record Type: Journal Article
• Authors: Xing, Yingying; Li, Di; Li, Longhua; Tong, Huamei; Jiang, Deli; Shi, Weidong
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 11(2021)
• Page Start: 7989
• Page End: 8001
• Publication Date: 2021-02-11
• Subjects: Electrocatalysis -- Hydrogen evolution reaction -- Co-doping -- Hydrogen adsorption energy -- Synergistic effect; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.12.037
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Electrocatalytic hydrogen evolution under alkaline media holds great promising in hydrogen energy production. Transition-metal sulfides (TMSs) are attractive for electrocatalytic alkaline hydrogen evolution, yet their catalytic performance is unsatisfactory owing to the sluggish water dissociation kinetics. Herein, a Mn/N co-doping strategy is proposed to regulate the water dissociation kinetics of Co9 S8 nanowires array grown on nickel foam thus improve the activity of hydrogen evolution reaction (HER). The optimal Mn/N co-doping Co9 S8 (Mn–N–Co9 S8 ) catalyst achieves low overpotentials of 102 and 238 mV at 10 and 100 mA cm −2 in the 1 M KOH solution, respectively, remarkably higher than the single-doping Mn–Co9 S8 and N–Co9 S8 as well as superior to many reported Co9 S8 -based HER electrocatalysts. Density functional theory (DFT) calculation results confirm that the water dissociation barrier of the Mn–N–Co9 S8 is reduced significantly owing to the synergistic co-doping of Mn and N, which accounts for the enhanced alkaline HER performance. This study offers an effective strategy to enhance the alkaline HER activity of TMSs by accelerating water dissociation kinetic via the cation and anion co-doping strategy. Graphical abstract: Image 1 Highlights: Mn–N–Co9 S8 nanotube array electrocatalyst supported on 3D nickel foam was prepared. The optimal sample achieves a low overpotential of 238 mV at 100 mA cm −2 . The co-doping and special structure are responsible for the high HER activity.