Amorphous Cu–W Alloys as Stable and Efficient Electrocatalysts for Hydrogen Evolution

Abstract

Cu and W are completely immiscible in equilibrium conditions, and neither of them is a good catalytic element for the electrochemical hydrogen evolution reaction (HER) due to their hydrogen adsorption Gibbs free energy (ΔG H) being too positive or negative, respectively. However, the combination of Cu with W could potentially result in a moderate ΔG H. In this study, a series of binary amorphous Cu–W alloys are fabricated via a magnetron sputtering method. The optimal HER catalytic performance is demonstrated when the nominal component is Cu50W50, showing an overpotential of only 65 mV at 10 mA cm–2 in 1 M KOH. Accordingly, density functional theory calculations show that the amorphous Cu50W50 alloy has a close-to-zero ΔG H compared to the pure Cu and W metals, accounting for its HER activity. In addition, the amorphous Cu50W50 alloy shows no obvious degradation at 100 mA cm–2 for 200 h, highlighting its long-term durability. This work provides a versatile strategy for the preparation of amorphous alloys with completely immiscible components and insights into the compositional design of nonprecious metal electrocatalysts for widespread applications.

Integrated Heterogeneous Engineering with the Vacancy Defect of Porous CoPv-MoxPv Nanosheets for an Accelerated Hydrogen Evolution Reaction

“…In addition, some peaks were derived from molybdenum phosphide, mainly Mo 4 P 3 (JCPDS Card 18-0846). In addition, it was noted that the comparison sample CoMo x P v /CNT-300 had no characteristic peaks, probably due to its amorphous state . The XRD pattern for the precursor of the CoMoO 4 /CNT is shown in Figure S1.…”

ZIF-67 Nanostructures Anchored on 3D Graphene Sheets: A Non-noble Electrocatalyst for Efficient Oxygen Evolution Reaction

“…Linear sweep voltammetry (LSV) measurements were performed at a scan rate of 5 mV s –1 in the potential window of 0 to 0.7 V vs Ag/AgCl. Tafel slopes were extracted from the LSV curves and fitted to the Tafel equation, η = a + b log j , where “η” represents the overpotential, “ a ” and “ b ” are constants, and “ j ” denotes current density . The potential values were converted to the reversible hydrogen electrode (RHE) scale using the following equation: E RHE = E Ag / Ag Cl + 0.197 + 0.059 × pH …”