Tungsten-Assisted Phase Tuning of Molybdenum Carbide for Efficient Electrocatalytic Hydrogen Evolution.

Title Tungsten-Assisted Phase Tuning of Molybdenum Carbide for Efficient Electrocatalytic Hydrogen Evolution.
Authors K. Zhang; G. Zhang; J. Qu; H. Liu
Journal ACS Appl Mater Interfaces
DOI 10.1021/acsami.7b14733
Abstract

Phase tuning during crystal phase transformation is an important but challenging step toward the development of effective hydrogen evolution reaction (HER) catalysts. Herein, we report on a feasible approach to achieve effective polycrystalline molybdenum carbides during transformation from ?-phase to ?-phase through the regulation of additive (tungsten) amount. Benefiting from the optimal Mo-C bond lengths and abundant active sites, molybdenum carbide prepared with a moderate addition of tungsten enhanced electrocatalytic activity and stability compared with pure ?-phase and ?-phase Mo2C in the HER, and only required an overpotential of 148 and 93 mV to drive 20 mA cm-2 of current density in 0.5 M H2SO4 and 1.0 M KOH, respectively.

Citation K. Zhang; G. Zhang; J. Qu; H. Liu.Tungsten-Assisted Phase Tuning of Molybdenum Carbide for Efficient Electrocatalytic Hydrogen Evolution.. ACS Appl Mater Interfaces. 2018. doi:10.1021/acsami.7b14733

Related Elements

Tungsten

See more Tungsten products. Tungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f14 5d4 6s2. Tungsten Bohr ModelThe tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance. Elemental TungstenTungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO4) and wolframite [(Fe,Mn)WO4]. In reference to its density, Tungsten gets its name from the Swedish words tung and sten, meaning heavy stone.

Molybdenum

See more Molybdenum products. Molybdenum (atomic symbol: Mo, atomic number: 42) is a Block D, Group 6, Period 5 element with an atomic weight of 95.96. Molybdenum Bohr ModelThe number of electrons in each of molybdenum's shells is [2, 8, 18, 13, 1] and its electron configuration is [Kr] 4d5 5s1. The molybdenum atom has a radius of 139 pm and a Van der Waals radius of 209 pm. In its elemental form, molybdenum has a gray metallic appearance. Molybdenum was discovered by Carl Wilhelm in 1778 and first isolated by Peter Jacob Hjelm in 1781. Molybdenum is the 54th most abundant element in the earth's crust. Elemental MolybdenumIt has the third highest melting point of any element, exceeded only by tungsten and tantalum. Molybdenum does not occur naturally as a free metal, it is found in various oxidation states in minerals. The primary commercial source of molybdenum is molybdenite, although it is also recovered as a byproduct of copper and tungsten mining. The origin of the name Molybdenum comes from the Greek word molubdos meaning lead.

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