Au/Ni12P5 core/shell single-crystal nanoparticles as oxygen evolution reaction catalyst

Abstract

We have demonstrated the improved performance of oxygen evolution reactions (OER) using Au/nickel phosphide (Ni 12 P 5 ) core/shell nanoparticles (NPs) under basic conditions. NPs with a Ni 12 P 5 shell and a Au core, both of which have well-defined crystal structures, have been prepared using solution-based synthetic routes. Compared with pure Ni 12 P 5 NPs and Au-Ni 12 P 5 oligomer-like NPs, the core/shell crystalline structure with Au shows an improved OER activity. It affords a current density of 10 mA/cm 2 at a small overpotential of 0.34 V, in 1 M KOH aqueous solution at room temperature. This enhanced OER activity may relate to the strong structural and effective electronic coupling between the single-crystal core and the shell.

Tuning Interfacial Structures for Better Catalysis of Water Electrolysis

“…During heating, Co ions were reduced to a shell layer of metallic Co on the surface of Ag NPs, which finally allowed the phosphating process under high‐temperature aging with TPP as the P source. Similar one‐pot procedures have also been proposed for the fabrication of Au/Ni 12 P 5 (Figure D) and Fe 3 O 4 /Ni x P (Figure E) core–shell NPs by the groups of Wang and Pradhan, respectively.…”

Enhanced OER Performances of Au@NiCo2S4 Core-Shell Heterostructure

“…The decrease of R t is due to the interaction between the Au NP and the NiCo 2 S 4 shell, which can enhance the conductivity and shorten the length of charge diffusion [39]. The double-layer capacitance (C d ) of the NPs surface is reflected by the Y 0 value of the CPE, which represents the location of the absorbed molecules, and is related to the electrochemical surface area [36]. The Y 0 value of Au@NiCo 2 S 4 NPs is much larger than that of bare NiCo 2 S 4 NPs, as shown in Table S4, indicating that its effective surface area is larger than that of bare NiCo 2 S 4 NPs, and that Au@NiCo 2 S 4 core-shell NPs have more active sites and exhibit better OER activity.…”

“…To further enhance the OER catalytic properties and promote the application of bimetallic sulfides, designing heterostructures composed of bimetallic sulfide and metal is one of the most effective methods [31][32][33][34][35]. The enhanced physicochemical properties of metal-semiconductor heterostructures are mainly due to the interaction between metal and semiconductor [36,37]. Compared with yolk-shell and oligomer-like heterostructures, the core-shell heterostructure has the maximum contact interface, which can effectively enhance electron transmission along the interface, improve the electrical conductivity, and optimize the electronic structure [9,37,38].…”

“…This is because the Au@NiS x core-shell heterostructure has a larger contact interface, leading to promoted charge transfer and higher conductivity [39]. The OER activity of Au/Ni 12 P 5 core-shell heterostructure has also been demonstrated to be improved by the electron interaction between Au and Ni 12 P 5 [36].…”

Au@Co2P core/shell nanoparticles as a nano-electrocatalyst for enhancing the oxygen evolution reaction

“…The Au@Co 2 P core/shell NPs were synthesized via a method based on our previous work. 34,35 Firstly, Co(acac) 2 (0.5 g) and oleylamine (OAm, 10 mL) were added into a three-necked ask, and mixed at 100 C for 60 min. Secondly, the prepared solution of HAuCl 4 $4H 2 O (10 mg mL À1 in toluene) was maintained at 100 C for 120 min under the protection of argon (40 mL min À1 ).…”