Core-shell trimetallic NiFeV disulfides and amorphous high-valance NiFe hydroxide nanosheets enhancing oxygen evolution reaction

Engineering NiMoO4/NiFe LDH/rGO multicomponent nanosheets toward enhanced electrocatalytic oxygen evolution reaction

“…In order to overcome these challenges, many effective strategies have been proposed, including modifying the surface and interface, 14,15 architecture engineering, 16,17 improving electronic conductivity, 18,19 etc . Among them, surface and interface engineering has been widely accepted as a promising route to modulate the surface and interface properties of catalysts, which not only boosts the exposure of surface active sites, but also facilitates the charge transfer via heterointerfaces during electrochemical reactions.…”

Vanadium-Based Trimetallic Metal-Organic-Framework Family as Extremely High-Performing and Ultrastable Electrocatalysts for Water Splitting

“…Apart from these experimental evidences, related theoretical proof has been also demonstrated by previous reports. ,,,,, For OER reaction, its reaction pathway in alkaline medium is based on the 4e-mechanism put forward by Norskov, as shown in equations (I–IV): (I) * + H 2 O → *OH + H + + e – (Δ G I ); (II) *OH → *O + H + + e – (Δ G II ); (III) *O + H 2 O → *OOH + H + + e – (Δ G III ); and (IV) *OOH → * + O 2 + H + + e – (Δ G IV ). Here, “*” represents the active sites on catalysts, Δ G I , Δ G II , Δ G III , and Δ G IV stand for the reaction Gibbs free energies .…”

“…Apart from these experimental evidences, related theoretical proof has been also demonstrated by previous reports. 25,29,30,37,47,48 When ΔG H* = 0 eV, the HER performance is optimal since the proton reduction rate and desorption rate of absorbed H on the surface of electrocatalyst can reach balance. As reported by previous studies, 25,29,30 the introduction of vanadium can significantly reduce the Gibbs free energy of the rate-determining step (RDS) and adsorption energy during OER and HER reaction processes.…”

In Situ Anodic Oxidation Tuning of NiFeV Diselenide to the Core–Shell Heterojunction for Boosting Oxygen Evolution

“…Furthermore, we operated the XPS spectra (Figure 4f−i) to determine the surface composition and oxidation states of the outer shell material. The fitted peaks of Ni 2p at 855.6 and 873.3 eV can be ascribed to Ni 3+ , 12,51 which indicate the total oxidation of the Ni element during the ISAO process. A large number of high-valence Ni 3+ are favorable to improve the OER activity of the amorphous NiFe hydroxide outer shell.…”

“…41,42 The three well-fitted peaks of V 2p for Fe,V-NiSe 2 located at 514.8, 516.1, and 517.1 eV suggest that V contain +3, +4, and +5 oxidation states, respectively. 12,43 These multivalent vanadium cations can enhance the intrinsic conductivity of the Fe,V-NiSe 2 sample. 23 The Se 3d spectra (Figure 3d) are divided into 3d 5/2 (54.2 eV) and 3d 3/2 (55.1 eV) doublets, which reveals the presence of Se 2 2− in various diselenides.…”