Ni-Fe layered double hydroxides for oxygen evolution Reaction: Impact of Ni/Fe ratio and crystallinity. (15th December 2021)

• Record Type: Journal Article
• Authors: Wilhelm, Manon; Bastos, Alexandre; Neves, Cristina; Martins, Roberto; Tedim, João
• Is Part Of: Materials & design. Volume 212(2021)
• Publication Date: 2021-12-15
• Subjects: Oxygen Evolution Reaction -- Electrocatalysis -- Layered Double Hydroxides -- Overpotential -- Crystallinity; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2021.110188
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: Overpotential of NiFe LDHs was 333–411 mVRHE, lower than for RuO2 (507 mVRHE ). Increase in LDH crystallinity led to an increase in OER overpotential. OER overpotential did not change for Ni/Fe ratio between 2:1 and 4:1. O2 measurements with microelectrode revealed a non-tafelian behaviour of NiFe LDHs. Abstract: The Oxygen Evolution Reaction (OER), half-reaction of the water-splitting process for hydrogen production, suffers from sluggish kinetics. NiFe materials appeared as interesting catalytic materials for this reaction in alkaline electrolyzers and have been studied, particularly in the form of NiFe Layered Double Hydroxides (LDH). However, the impact of the specificity of the atomic arrangement in the LDH and of its composition on the catalytic efficiency of the material are still unknown. Herein, LDH are synthesized with Ni/Fe ratios from 2 to 4 and different levels of crystallinity to assess their electrocatalytic behavior in 0.1 M KOH. Statistical analysis of the electrochemical results allows to highlight that, while no effect from the atomic ratio is observed, an increase in the crystallinity of the LDH seem detrimental to the catalytic efficiency.