Magnetic and Electrocatalytic Properties of Nanoscale Cobalt Boride, Co₃B

Abstract

The use of low-temperature solution synthesis followed by a brief annealing step allows metastable single-phase Co3B nanoparticles to be obtained, with sizes ranging from 11 nm to 22 nm. The particles are ferromagnetic with a saturation magnetization of 91 A m 2 kg-1 (corresponding to 1.02 μB/Co) and a coercive field of 0.14 T at 5 K, retaining the semi-hard magnetic properties of bulk Co3B. They display a magnetic blocking temperature of 695 K and a Curie temperature near 710 K, but the measurement of these high-temperature properties was complicated by decomposition of the particles at these high temperatures. Additionally, the nanoparticles of Co3B were investigated as an electrocatalyst in the oxygen evolution reaction and showed a low onset potential of 1.55 V vs. RHE. XPS measurements were performed before and after the electrocatalytic measurements to study the surface of the catalyst, to pinpoint what appear to be the active surface species.

Intermetallic borides: structures, synthesis and applications in electrocatalysis

“…[126][127][128][129] Transition metal borides as a class of non-oxide OER electrocatalysts received much attention in recent years. Particularly some metal-rich borides exhibited promising OER activity, mainly including cobalt borides (e.g., Co 2 B, Co 3 B), 130,131 iron borides (e.g., Fe 2 B), 132 nickel borides (e.g., Ni 2 B, Ni 3 B), 45,133 and their solid solutions (e.g., Ni x Fe 2−x B). 134 For example, our group performed a boronizing treatment on diverse metal sheets (including Fe, Co, Ni, NiFe alloys and steel sheets) to produce M 2 B layers on the corresponding metal sheets as oxygen evolution electrodes ( Fig.…”

Solid-state Thermoelectric Characteristics of NiII, FeII, CoII, and CuII Borohydrides

“…On the other hand, metal borides (M-Bs) [26][27][28][29][30][31][32][33][34] and metal borohydrides (M-BHs) [35][36][37][38][39][40][41][42][43][44][45] of p-, d-, and f-block elements have become in the spotlight as solid-state materials.…”

“…Nevertheless, these two classes of materials are closely related where M-BHs undergo dehydrogenation to yield M-Bs when subjected to heat (300-400 °C) under an inert atmosphere [35][36][37][38]40]. These M-Bs are generally classified as boron-rich (MB12 -MB70) and metal-rich (M2B-to-M5B), exhibiting a variety of structures, including isolated B atoms, chains, layer, and clusters [26][27][28][29][30][31][32][33][34]. Currently, the exceptional structural, hardness and thermal properties of M-Bs receive increasing attention as hard refractory (TiB6), hard magnets (Nd2Fe14B), battery electrodes, conducting ceramics (ZrB2, HfB2), electro-catalysis, and superconducting (MgB2) materials [26][27][28][29][30][31][32][33][34].…”

“…These M-Bs are generally classified as boron-rich (MB12 -MB70) and metal-rich (M2B-to-M5B), exhibiting a variety of structures, including isolated B atoms, chains, layer, and clusters [26][27][28][29][30][31][32][33][34]. Currently, the exceptional structural, hardness and thermal properties of M-Bs receive increasing attention as hard refractory (TiB6), hard magnets (Nd2Fe14B), battery electrodes, conducting ceramics (ZrB2, HfB2), electro-catalysis, and superconducting (MgB2) materials [26][27][28][29][30][31][32][33][34]. Meanwhile, solid-state M-BHs continue to attract attention as H-storage materials in solid fuels, electrolytes in batteries, and luminescence and magnetic applications [35][36][37][38][39][40][41][42].…”

Efficient Oxygen Evolution Electrocatalyst by Incorporation of Nickel into Nanoscale Dicobalt Boride

“…observed in 1980 that certain transition metal borides were active electrocatalysts for the oxygen evolution reaction (OER) [8,9] . Recently, binary metal borides with Co, [10–16] Fe, [12,15,17–19] and Ni, [11,12,14,19–21] were found to show high catalytic efficiencies for the OER. A recent review on the application of metal borides as electrocatalyst is given by Gupta et al [7] .…”