Surface reconstruction of NiCoP pre-catalysts for bifunctional water splitting in alkaline electrolyte

Recent Progress on Structurally Ordered Materials for Electrocatalysis

“…[ 46 ] Moreover, for transition‐metal‐based materials, especially those containing a 3d transition metal, independent of the material types (e.g., oxides, alloys, (oxy)hydroxides, and sulfides) and the synthetic routes, the surface formation of (oxy)hydroxides was confirmed and (oxy)hydroxides were demonstrated as the real active sites for the OER. [ 47 ] It was found that Fe‐based intermetallic Fe 6 Ge 5 would undergo a structural transformation into a core‐shell‐like structure. In detail, conductive intermetallic Fe 6 Ge 5 acts as the core, and the in situ‐formed amorphous material (K x FeO 2 H y ) serves as the shell.…”

Realizing electrochemical transformation of a metal–organic framework precatalyst into a metal hydroxide–oxy(hydroxide) active catalyst during alkaline water oxidation

“…are observed to undergo steady changes on the surface and sub-surface, or as a whole because of their reactivity at a high anodic potential. 3,20,22,29,30,[47][48][49][50][51][52][53][54][55] Therefore, the transition metal-based catalyst works as the "precatalyst," rather than the real catalyst. A drastic reconstruction of the precatalyst occurs leading to phase transformation and morphological and compositional variation under the oxidizing anodic potential.…”

“…A drastic reconstruction of the precatalyst occurs leading to phase transformation and morphological and compositional variation under the oxidizing anodic potential. 3,20,22,29,30,[47][48][49][50][51][52][53][54][55] As a result, M(OH) 2 -M(O) x (OH) y is formed on the surface of the particles or the whole material has been transformed into the active catalyst (Fig. 1).…”

“…The generated over-layer of the active catalyst on the surface of the particles was found to be amorphous in nature for many catalysts forming a core-shell structure. 3,20,22,29,30,[47][48][49][50][51][52][53][54][55] On the other hand, small and ultra-small nanoparticles underwent complete amorphization during alkaline water oxidation. 3,20,22,29,30,[47][48][49][50][51][52][53][54][55] This process of activation is irreversible for most of the precatalysts and leads to a signicant improvement of the water oxidation activity.…”

Nitrogen-Doped Oxygenated Molybdenum Phosphide as an Efficient Electrocatalyst for Hydrogen Evolution in Alkaline Media

“…Therefore, the focus has been shifted toward finding the electrocatalysts which are earth abundant and inexpensive and possessed a similar or better performance than precious metals. Recently, transition-metal alloys, nitrides, sulfides, oxides, selenides, phosphides, borides, and carbides have been studied (Fosdick et al, 2014 ; Yuan et al, 2016 ; Zhang et al, 2017 ; Zhao et al, 2018 ; Lian et al, 2019 ; Zou et al, 2020 ). Out of these materials, transition metal phosphides (TMPs) have shown superior activity and stability (Ren Q. et al, 2019 ; Zou et al, 2020 ).…”