HfN Nanoparticles: An Unexplored Catalyst for the Electrocatalytic Oxygen Evolution Reaction

Abstract

Water electrolysis is one of the most promising methods to produce H 2 and O 2 as high potential fuels.Comparing the two half-reactions,the oxygen evolution reaction (OER) is the more difficult to be optimizedand still relies on expensive noble metal-based catalysts such as Ru or Ir.Inthis paper,we prepared nanoparticles of HfN and Hf 2 ON 2 and tested them for the OER for the first time.The HfN sample,i np articular, showed the highest activity,requiring an overpotential of only 358 mV at 10 mA cm À2 in Fe-free electrolyte and, abovea ll, exhibiting long-term stability.T his result places this system amongst one of the most promising catalysts for OER tested to date,i nt erms of sustainability,a ctivity and stability.T he prepared nanoparticles are small (less than 15 nm in diameter), well-defined in shape and crystalline,a nd were characterised before and after electrochemical testing also via electron microscopy(EM), powder X-ray diffraction (PXRD) and X-ray photoelectron spectroscopy(XPS). Scheme 1. The two half-reactions for the water-splitting process:H 2 is produced at the cathode (HER) and O 2 at the anode (OER). [1] Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under https://doi.

Spinel of Nickel-Cobalt Oxide with Rod-Like Architecture as Electrocatalyst for Oxygen Evolution Reaction

“…It can be further concluded that the synergy of spheres and rods provided efficient electrocatalysts with superior stability and promising activity. As mentioned before, Hf nanoparticles have been recently reported as a novel electrocatalyst with relatively low values of overpotential at 10 mAcm −2 (358 mV) and Tafel slope of 85 mV/dec [ 5 ]. Therefore, it is desired to study these materials in greater detail and various morphology to reveal a clear correlation between spinels shape and their electrochemical performance.…”

“…The choice is mostly between noble metal and their oxides such as Pt, Ru, RuO 2 , Ir, IrO 2 . Furthermore, it is worth mentioning that Giordano et al have recently reported Hf nanoparticles for OER, which exhibiting interesting performance and low over-potential [ 5 ].…”

Recent Advances in Transition Metal Carbide Electrocatalysts for Oxygen Evolution Reaction

“…Due to the combination of nitrogen atoms in graphite structure, nitrogen-doped carbon materials can perform impressive ORR catalytic activity. In addition, Defilippi et al [82] took advantage of the sol-gel technique and successfully synthesized HfN NPs (less than 15 nm in diameter), which exhibited a quite low overpotential of 358 mV at 10 mA•cm -2 and long term stability as an OER electrocatalyst. This recent study indicates that metal nitrides possess high conductivity, stability, and melting point, and these properties make them qualified to be active both for ORR and OER.…”

Preparation of high entropy nitride ceramic nanofibers from liquid precursor for CO2 photocatalytic reduction

“…"High entropy" was firstly proposed by Cantor et al 7 and Yeh et al 8 in alloys, meanwhile, this concept has been extended to high entropy oxides, 4 high entropy carbides, 5 high entropy borides, 9 high entropy nitrides (HENs), [10][11][12] and so on. 13,14 Metal nitrides are kinds of metal compounds constructed by metal-nitrogen covalent bonds, which have attracted great attention due to their unique features, [15][16][17] such as high chemical stability, excellent physical properties, and diverse electrical characteristics. Likewise, some applications such as energy-storage, 11 wear-resistant coatings, [18][19][20] diffusion barriers for microelectronics 21,22 are achieved from HENs.…”