Ag/Cu nano alloy as an electrocatalyst for hydrogen production

In this paper, Ag/Cu alloy modified carbon paste electrode (Ag/Cu-CPE) was found as a highly active catalyst for electrochemical H2 production from acidic solution (0.5 M H2SO4). The morphology and structure of the catalyst was investigated with scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX) techniques, respectively. The electrochemical studies were done with cyclic voltammetry, linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS). Some important parameters including electrolyte type and catalyst amount in the electrode composition were optimized, which the best results were obtained in 0.5 M H2SO4 and 25% of the catalyst percent. Results showed compare to CPE, Cu-CPE and Ag-CPE when Ag/Cu-CPE is used, the onset potential shifts to more positive values, and the current density increases considerably. Also after applying successive cyclic voltammograms (CVs) on the electrode surface, the Ag/Cu nano alloy layer formed on the surface of electrode and this nano layer not only does not reduce the performance of HER, but by decreasing overvoltage and increasing current density, enhanced the hydrogen production.