Na₄Ni₃P₄O₁₅–Ni(OH)₂ core–shell nanoparticles as hybrid electrocatalysts for the oxygen evolution reaction in alkaline electrolytes

Abstract

Core(phosphate)–shell(Ni(OH)2–NiOOH) nanoparticles as stable OER electrocatalysts with low overpotentials of 250–290 mV were prepared by chemical and electrochemical conversion of phosphate in an alkaline medium.

Expansion of the multifunctionality in off-stoichiometric manganites using post-annealing and high pressure: physical and electrochemical studies

“…98 Thus, during electrolysis, phosphate compounds can be converted in situ to various forms of electrocatalysts. [98][99][100] Moreover, phosphates are good co-catalysts for the OER. 101 This is also evidenced by the results obtained here: the overpotential of the LMO materials for the OER process in the 0.5 M KH 2 PO 4 electrolyte is minimal (see Fig.…”

Heterostructured Mo‐Doped CoP on MXene Supports Enhanced the Alkaline Hydrogen Evolution Activity

“…The P‐2 p deconvoluted peak of Mo‐CoP/Ti 3 C 2 T x is red‐shifted by 0.1 eV compared to that of Mo‐CoP, proving the existence of heterostructure between Mo‐CoP and Ti 3 C 2 T x facilitating the electron transfer from Ti 3 C 2 T x to Mo‐CoP. The peak at 133.8 eV stems from the phosphate species on the surface of Mo‐CoP, which acted a significant role in water dissociation [50] and proton absorption [51–52] . In Figure 3(c), Co‐2 p peak involves Co 3+ (781.0 eV), Co 2+ (782.7 eV), Co 0 (778.2 eV) and satellite peaks (786.1 eV).…”

“…[49] The ZIF-67 particles attached to the exterior of the monolayer Ti 3 C 2 T x to form the ZIF-67/Ti 3 C 2 T x hybrids, and followed by the Na 2 MoO 4 etching and phosphorization treatment. It is revealed that a slight peak of Mo-ZIF-67/Ti 3 C 2 T x in Figure 1 stems from the phosphate species on the surface of Mo-CoP, which acted a significant role in water dissociation [50] and proton absorption. [51][52] In Figure 3…”

Surface reconstruction establishing Mott-Schottky heterojunction and built-in space-charging effect accelerating oxygen evolution reaction

“…Figure 1(a) shows the CV curve of the F-Ni(OH) 2 from 1 to 10 cycles. It is shown that the area and position of the Ni oxidation peak were changed from Ni 2+ to Ni 3+ as increasing the CV number, which indicates the controllable chemical state and composition of the materials [33,34]. Specifically, the area of the Ni oxidation peak (Ni 2+ to Ni 3+ ) gradually increases, and the onset potential shifts negatively due to a strong electron transfer, which suggests Ni(OH) 2 is gradually transformed into NiOOH [35].…”