Surface Reconstruction and Phase Transition on Vanadium–Cobalt–Iron Trimetal Nitrides to Form Active Oxyhydroxide for Enhanced Electrocatalytic Water Oxidation

Abstract

However, the sluggish kinetics of oxygen evolution reaction (OER) in the electrolysis of water dramatically hinders its development for practical applications. [3] One of the challenges is to develop electrocatalysts with low-cost, abundance, high stability, and high catalytic activity for OER. Noble-metal oxides (such as IrO 2 and RuO 2) are most widely employed as efficient OER catalysts, but their scarcity and high cost limit their commercial application. [4] Therefore, tremendous efforts have been devoted to exploring low-cost earthabundant metals and their compounds for high-efficient and stable OER. [5] Nonprecious transition metal-based compounds, such as sulfides, [4c,6] (oxy)hydroxides, [4a,7] oxides, [4b,8] and phosphides, [4b,9] have been reported for OER owing to their tunable electronic structures and abundant active sites. Recently, 3d transition metal nitrides (TMNs) have been recognized to be promising for the OER process, which are superior to oxides, hydroxides, and sulfides, because of high electrical conductivity and enriched active sites. [10] It should be noted here that the surfaces of TMNs are easily oxidized into oxides and hydroxides. For example, the surface of catalyst was converted to metal oxyhydroxide (*OOH) owing to fast surface reconstruction and phase transition during the electrochemical The sluggish oxygen evolution reaction (OER) is a pivotal process for renewable energy technologies, such as water splitting. The discovery of efficient, durable, and earth-abundant electrocatalysts for water oxidation is highly desirable. Here, a novel trimetallic nitride compound grown on nickel foam (CoVFeN @ NF) is demonstrated, which is an ultra-highly active OER electrocatalyst that outperforms the benchmark catalyst, RuO 2 , and most of the state-of-the-art 3D transition metals and their compounds. CoVFeN @ NF exhibits ultralow OER overpotentials of 212 and 264 mV at 10 and 100 mA cm −2 in 1 m KOH, respectively, together with a small Tafel slop of 34.8 mV dec −1. Structural characterization reveals that the excellent catalytic activity mainly originates from: 1) formation of oxyhydroxide species on the surface of the catalyst due to surface reconstruction and phase transition, 2) promoted oxygen evolution possibly activated by peroxo-like (O 2 2−) species through a combined lattice-oxygen-oxidation and adsorbate escape mechanism, 3) an optimized electronic structure and local coordination environment owing to the synergistic effect of the multimetal system, and 4) greatly accelerated electron 1. Introduction Developing renewable and ecofriendly energy sources/technologies is urgently required to address environmental pollution and energy crisis. [1] Electrically driven water splitting for the production of hydrogen and oxygen has been considered as one

Bridging electrocatalyst and cocatalyst studies for solar hydrogen production via water splitting

“…44 In addition, researchers have discovered that chalcogenides and phosphides containing two or more types of metals can also function as excellent OER ECs. [44][45][46][47][48][49][50][51][52][53][54] 2.1.3 Bifunctional compounds as electrocatalysts. While exploring new EC materials, researchers have identied various compounds that are highly-active for both HER and OER.…”

Multidimensional Nonstoichiometric Electrode Materials for Electrochemical Energy Conversion and Storage

“…[260] Other dopants such as V, Mn, Cu, Ru, and Al are also available to boost the electrochemical performance of Fe/Co/Nibased (oxy)hydroxide catalysts. [54,77,[261][262][263][264][265] Particularly, the highvalence W is a structurally versatile dopant to modulate the electronic structure and optimize the intermediates adsorption for accelerating the OER kinetics. [36,176,266] Recently, Zhang et al reported the doping of several metal elements (i.e., W, Mo, Nb, Ta, and Re) in high oxidation states to modify the redox cycles of NiFe and FeCo oxyhydroxides.…”

Engineering Lattice Oxygen Activation of Iridium Clusters Stabilized on Amorphous Bimetal Borides Array for Oxygen Evolution Reaction

“…Among various OER catalysts,3 dt ransition metal materials have been regarded as promising electrocatalysts in alkaline medium due to the formation of oxyhydroxide intermediates as favorable active sites for OER. [16][17][18][19][20][21] It is evident to identify the role of the surface reconstruction and termination, regulating the surface structure of the catalysts and the oxidation kinetics.M eanwhile,m etal supported catalysts offer ap romising approach to optimize the OER activity owe to the interfacial interaction of metals and the supports.Uptonow,noble metal oxides,such as iridium (Ir) and ruthenium (Ru) oxides,are the most superior catalysts for OER. [22] Alarge number of materials present enhanced OER performance by the decoration of metal clusters on the supported electrocatalysts,s uch as organic molecule, [23] carbon nanotubes, [24] metal oxides [25] and phosphides.…”