Interfacial engineering of hierarchical ultra-thin NiCo-LDH nanosheet superstructures nanofiber for water cracking electrocatalysis

• Published in: Journal of alloys and compounds 2025-01, Vol.1010, p.178041, Article 178041
• Main Authors: Cao, Hongshuang, Liu, Bo, Bai, Jie, Li, Chunping, Xu, Guangran
• Format: Article
• Language: English
• Subjects: Electrocatalyst; NiCo-LDH; Superstructures; Water cracking electrocatalysis
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.178041

The rational design and synthesis of stable transition metal electrocatalysts for the efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) represent a pressing necessity and a significant challenge. Layered double hydroxide (LDH) based catalysts provide abundant active site properties for electrochemical reactions due to their flexible adjustment and high dispersion of metal elements and interlayer anions. However, the limited capacity for electron transport and inadequate exposure of the active site continue to hinder their activity and stability. In this study, hierarchical fibrous superstructures were constructed by anchoring uniformly ultrathin NiCo-LDH nanosheets onto the interface of nickel-based carbon nanofibers (Ni1Co2-LDH/Ni/NiO-CNFs) through an electrospinning and electrodeposition process. The special lamellar structure and nanofibers network of Ni1Co2-LDH/Ni/NiO-CNFs results in a large electroactive surface area and enhanced electron transport capacity, improving HER and reactivity of OER in alkaline environments. Density-functional theory (DFT) calculations reveal that Ni/NiO-CNFs and NiCo-LDH have abundant interfacial active sites with enhanced electron transport at the interface, which accelerates the electrochemical reaction process. The catalyst exhibited excellent catalytic activity in a 1.0 M KOH electrolyte, achieving an overpotential of 272 mV for the oxygen evolution reaction (OER) and 152 mV for the hydrogen evolution reaction (HER). In alkaline conditions Ni1Co2-LDH/Ni/NiO-CNFs exhibits wonderful water decomposition achievement, at an applied voltage of 1.72 V, a current density of 10 mA cm−2 can be achieved. This study explores a promising approach towards achieving an optimal and cost-effective Ni-based hydroxide electrocatalyst that will enable efficient water splitting on an overall basis. [Display omitted] •The special lamellar structure of NiCo-LDH provides a larger specific surface area for the catalyst.•High conductivity and oxidation of Ni/NiO-CNFs promote electron transfer to improve electrocatalytic activity.•Conducting metals coupled at the interface play a key role in the regulation of electron redistribution.•The electrocatalytic performance is superior to other reported related materials.