The impact of ultrasonic parameters on the exfoliation of NiFe LDH nanosheets as electrocatalysts for the oxygen evolution reaction in alkaline media

Abstract

Highlights The influence of parameters on ultrasonic exfoliation of the NiFe LDH in pure water was studied. Various Concentration, amplitude, sonication times were investigated for exfoliation. The optimum condition of ultrasonic exfoliation of 60%, 10 mg mL −1 and 15 min. The best OER activity shows 250 mV overpotential at a current density of 10 mA cm −1. Enriched Fe 3+ were found on the surface of the exfoliated NiFe LDH.

Rational Design and Preparation of Pt–LDH/CeO2 Catalyst for High-Efficiency Photothermal Catalytic Oxidation of Toluene

“…Stepped thickening of Pt–LDH/CeO 2 consolidates that the structure of the catalyst is CeO 2 -capsuled inside the skeleton of CoAl–LDH, consistent with the results of ACTEM. The images prove that the LDHs were exfoliated successfully. , Because of the lamellar structure of LDH, the crystal growth may lead to the enlarged size of the sheet when the metal ions were nucleated on CeO 2 . The new nucleated site may need high energy than the crystal growth, leading to the dispersed LDH dots on the LDH sheet.…”

“…The images prove that the LDHs were exfoliated successfully. 29,30 Because of the lamellar structure of LDH, the crystal growth may lead to the enlarged size of the sheet when the metal ions were nucleated on CeO 2 . The new nucleated site may need high energy than the crystal growth, leading to the dispersed LDH dots on the LDH sheet.…”

Recent Advances of Modified Ni (Co, Fe)-Based LDH 2D Materials for Water Splitting

“…In general, the traditional LDHs are layered stacked structures, which not only shield a large number of catalytic active sites, but also inhibit the electron and mass transfer during electrocatalytic reactions over the catalyst. Therefore, it can be stripped into ultrathin nanosheets with smaller sizes by the exfoliation strategy to significantly enhance electrocatalytic performance [ 125 , 126 , 127 , 128 , 129 ]. The peeled single-layer ultra-thin LDHs nanosheets provide a large surface area and more electrochemically active sites, thus facilitating the reaction with reactants.…”

“…Additionally, the ultrasonic treatment is one of the indispensable methods to peel off 2D layered materials. Zheng et al explored the effect of exfoliating NiFe-LDH on the performance of the catalyst OER under different ultrasonic conditions (including suspension concentration, sonification times, and amplification in water) [ 127 ]. TEM images showed that the stacked NiFe-LDH nanolayers were peeled off into ultra-thin layered structures, and the thickness could even reach 0.227 nm ( Figure 15 k,l).…”

Facile deposition of FeNi/Ni hybrid nanoflower electrocatalysts for effective and sustained water oxidation

“…Similarly, various nickel-iron combinations have shown promising results for OER catalysis. 32,33 These studies have indicated that the catalyst fabrication process, morphology and support material are the important parameters which contribute towards higher efficiency of the OER. It has been observed that previous OER studies based on the NiFe electrocatalyst used nano powders, which certainly require some polymer binders (like Naon) for better adhesion with the current collector.…”