Mechanochemical‐Assisted Synthesis of High‐Entropy Metal Nitride via a Soft Urea Strategy

Abstract

Crystalline high-entropy ceramics (CHC), a new class of solids that contain five or more elemental species, have attracted increasing interest because of their unique structure and potential applications. Up to now, only a couple of CHCs (e.g., high-entropy metal oxides and diborides) have been successfully synthesized. Here, a new strategy for preparing high-entropy metal nitride (HEMN-1) is proposed via a soft urea method assisted by mechanochemical synthesis. The as-prepared HEMN-1 possesses five highly dispersed metal components, including V, Cr, Nb, Mo, Zr, and simultaneously exhibits an interesting cubic crystal structure of metal nitrides. By taking advantage of these unique features, HEMN-1 can function as a promising candidate for supercapacitor applications. A specific capacitance of 78 F g is achieved at a scan rate of 100 mV s in 1 m KOH. In addition, such a facile synthetic strategy can be further extended to the fabrication of other types of HEMNs, paving the way for the synthesis of HEMNs with attractive properties for task-specific applications.

Gassing Behavior of High‐Entropy Oxide Anode and Oxyfluoride Cathode Probed Using Differential Electrochemical Mass Spectrometry

“…HEOs are a class of materials where a large number of different (incorporated) elements increases the configurational entropy, leading to entropy stabilization . The concept of entropy stabilization was first applied to metallic alloy systems and later transferred to ionic and covalently‐bonded structures . For high‐entropy materials, a single‐phase crystal structure can be achieved when the Gibbs free energy is negative or, in other words, when the entropy term is greater than the enthalpy of mixing .…”

Synthesis of Ru‐Doped VN by a Soft‐Urea Pathway as an Efficient Catalyst for Hydrogen Evolution

“…37‐0768), respectively, suggesting the successful nitrogenization of VOCl 3 precursor. The wide peak at about 22° is attributed to carbon, which is derived from thermal decomposition of urea . In addition, no obvious peaks of metallic Ru or Ru oxides can be identified.…”

“…The wide peak at about 22°is attributed to carbon, which is derived from thermal decomposition of urea. [54] In addition, no obvious peaks of metallic Ru or Ru oxides can be identified. Moreover, the Ru-VN-3 with increasing ruthenium loading (6 at%) exhibits similar diffraction peaks as the RuÀ VN-2 sample ( Figure S3).…”

Room‐Temperature Synthesis of High‐Entropy Perovskite Oxide Nanoparticle Catalysts through Ultrasonication‐Based Method

“…The highentropyp erovskite oxidesw ere synthesized as monodispersed, spherical nanoparticles with an average crystallite sizeo fa pproximately 5.9 nm. Examples include high-entropy metal dibor-ides, [4] high-entropy nitrides, [8,9] and high-entropy metal oxides (HEMOs). Notably, the entropically-driven stability of Ru/BaSrBi(ZrHfTiFe)O 3 with excellent dispersion of Ru in the perovskite phase bestowed the nanoparticles of Ru/BaSrBi(ZrHfTiFe)O 3 with good catalytic activity for CO oxidation.…”

“…[1][2][3][4][5][6] HEMs are based on the premise of incorporatingm ultiple components (usually five or more) into as ingle crystal phase to attain unique combination of properties that are otherwise unattainable in conventional solid solutions. Examples include high-entropy metal dibor-ides, [4] high-entropy nitrides, [8,9] and high-entropy metal oxides (HEMOs). Examples include high-entropy metal dibor-ides, [4] high-entropy nitrides, [8,9] and high-entropy metal oxides (HEMOs).…”