Tungsten-inert gas welding electrodes as low-cost, green and pH-universal electrocatalysts for the hydrogen evolution reaction

Abstract

Large-scale electrolytic production of hydrogen, as the most important energy carrier, requires low-cost and easily available electrocatalysts. Herein, different tungsten-inert gas (TIG) welding electrodes, namely, pure tungsten (W), zirconiated tungsten (W-Zr), ceriated tungsten (W-Ce) and lanthanated tungsten (W-La) electrodes, are introduced as low-cost, green and pH-universal electrocatalysts for the hydrogen evolution reaction (HER). The morphology, microstructure and composition of these electrodes have been investigated using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) and elemental mapping techniques. The electrocatalytic activity of the electrodes has been studied under acidic, basic and neutral conditions using linear sweep voltammetry (LSV), open circuit potential (OCP) measurements and electrochemical impedance spectroscopy (EIS) and the values of the onset potential (E_onset), overpotential at 10 mA cm⁻² (η₁₀), Tafel slope, OCP and charge transfer resistance (R_ct) have been obtained for each electrode. It can be claimed that among all the studied electrodes, the W-La electrode shows the best electrocatalytic performance according to the values of E_onset, η₁₀, OCP, and R_ct.