Gold Nanocluster‐Decorated Nickel Nitride as Stable Electrocatalyst for Oxygen Evolution Reaction in Alkaline Media

Abstract

Water electrolysis has received tremendous interest for energy conversion. This is due to its intrinsic eco‐friendliness, and plausibly high efficiencies. However, the efficiency is hampered by sluggish kinetics of the oxygen evolution reaction (OER) at the anode. In this work, co‐precipitation method followed by nitridation is used for fabricating highly efficient and stable Au‐decorated Ni3N electrocatalyst for OER activity in alkaline solution. The as‐prepared 2 wt % Au at Ni3N (2 %Au/Ni3N) nanoflower exhibits remarkable OER. Current density of 10 mA cm−2, Tafel slope of 52 mV/dec, a relatively small overpotential of ∼280 mV, and 94.8 % activity retention for over 10 hour of continuous operation are observed. This remarkable performance is one of the best OER results known so far for noble metal‐supported nanostructured materials using alkaline solution as the electrolyte. From experimental results and calculations thereby, it is found that the Au nanocluster can effectively regulate Ni3N electronic structure, and reduce the energy barrier associated with OER activity. The synthesis approach given here not only provides a highly efficient electrocatalyst for energy conversion, but also offers a platform for controlling structural characteristics, thereby tuning the catalytic properties of the Au/Ni3N nanoflowers.

Electrochemical behavior of a Ni3N OER precatalyst in Fe-purified alkaline media: the impact of self-oxidation and Fe incorporation

“…This is because almost all the reported Ni 3 N-based electrocatalysts have been tested in unpurified KOH electrolyte that contains trace quantities of Fe. [23][24][25][26][27][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] As one example, Shalom et al prepared the Ni 3 N/Ni(OH) 2 electrocatalysts and tested them for the OER in both commercial and Fe-free 1 M KOH aqueous solutions. 22 As the Ni 3 N/Ni(OH) 2 electrocatalysts demonstrated almost the same OER activities, they concluded that the influence of Fe impurities on the OER activity of their samples was minor.…”

A Review of Transition Metal Boride, Carbide, Pnictide, and Chalcogenide Water Oxidation Electrocatalysts

“…Hence, this electrocatalyst is regarded as “unknown” in Table . Similarly, even though the authors provided specific post-OER characterization results, which cannot be authoritative evidence to check the oxidation degree of the transition metal nitride and identify the real OER active species, we classify their reported nitrides as “unknown” in Table . ,,,,, …”

On the Roles of Electron Transfer in Catalysis by Nanoclusters and Nanoparticles

“…[210] AuNCs are the best defined and most numerous NCs and are excellent candidates for electrocatalysis when they are stabilized by other materials. [37,[209][210][211][212][213][214][215][216][217][218] Well-defined NCs of other late transition metals such as Ni, [219] Pt, [220,221] Ru [222] and Ir [223] have also, although more rarely, been shown to be efficient water-splitting electrocatalysts, and doping nanoclusters with another metal proved particularly effective. [224][225][226][227]…”