A simple femtosecond laser alloying process is applied under two different process gases nitrogen and air to create novel molybdenum-nickel alloyed and surface enhanced catalysts. A three-day electrochemical test protocol is applied in an alkaline half-cell at 298 K and 353 K to examine the catalytic activity and initial degradation mechanisms in the hydrogen evolution reaction. It is found, that the surface enhancement and the stability of the electrode significantly depends on the process gas. Molybdenum is degraded at the beginning of the test protocol, but it is shown that higher concentrations are not necessarily required for an increase performance. The highest catalytic activity on an electrode alloyed with molybdenum under nitrogen emerges in a steady state operation at 353 K. An overpotential of 135 mV at-100 mA cm-2 is measured. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

An entirely femtosecond laser (fs-laser) based process for the production of stable, enlarged and alloyed nickel surfaces is presented. The process allows the use of metal foils and aqueous salt solutions as alloying element sources. We alloy iron from an aqueous element source as well as molybdenum and cobalt from commercially available foils on nickel mesh surfaces without further coating process. It is shown that the content of alloyed iron on the nickel mesh surface structured with the fs-laser depends on the concentration of the aqueous iron(II) sulfate solution used. The alloy content of cobalt and molybdenum is controlled by adjustable laser parameters. Cross-sections prepared by a focused ion beam and subsequent energy dispersive X-ray spectroscopy shows that molybdenum and nickel form alloyed nanoscale particles on the structured nickel surface. The combination of an aqueous iron(II) sulfate solution and a molybdenum metal foil leads to a ternary nickel-molybdenum-iron surface alloy. The presented fs-laser alloying process can be applied to further metal combinations and offers the potential to create new materials and properties.