Accelerated oxygen evolution kinetics on NiFeAl-layered double hydroxide electrocatalysts with defect sites prepared by electrodeposition. (5th November 2019)

• Record Type: Journal Article
• Authors: Li, Huixi; Zhang, Lingling; Wang, Shengping; Yu, Jingxian
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 54(2019)
• Page Start: 28556
• Page End: 28565
• Publication Date: 2019-11-05
• Subjects: Electrodeposition -- Electrocatalyst -- Layered double hydroxides -- Defect -- Oxygen evolution reaction; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.09.155
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: NiFe layered double hydroxides (LDHs) is considered to be one of the LDHs electrocatalyst materials with the best electrocatalytic oxygen evolution properties. However, its poor conductivity and inherently poor electrocatalytic activity are considered to be the limiting factors inhibiting the electrocatalytic properties for oxygen evolution reaction (OER). The amorphous NiFeAl-LDHs electrocatalysts were prepared by electrodeposition with nickel foam as the support, and the D-NiFeAl-LDHs electrocatalyst with defect sites was then obtained by alkali etching. The mechanism of catalysts with defect sites in OER was analyzed. The ingenious defects can selectively accelerate the adsorption of OH −, thus enhancing the electrochemical activity. The D-NiFeAl-LDHs electrocatalyst had higher OER electrocatalytic activity than NiFe-LDHs electrocatalyst: its accelerated OER kinetics were mainly due to the introduction of iron and nickel defects in NiFeAl-LDHs nanosheets, which effectively adjusted the surface electronic structure and improved OER electrocatalytic performance. There was only a low overpotential of 262 mV with the current density of 10 mA cm −2, and the Tafel slope was as low as 41.67 mV dec −1 . The OER electrocatalytic performance of D-NiFeAl-LDHs was even better than those of most of the reported NiFe-LDHs electrocatalysts. Highlights: Successfully preparing amorphous NiFeAl-LDHs electrocatalyst by electrodeposition. Alkali etching treatment successfully introduces Ni 2+ and Fe 3+ defect sites. The defect sites can improve the amount of Ni 3+, accelerating the adsorption of OH − . The mechanism of catalysts with defect sites in oxygen evolution reaction was given.