Synthesis of Gold Nanoparticles and Incorporation to a Porous Nickel Electrode to Improve its Catalytic Performance Towards the Hydrogen Evolution Reaction

Abstract

[EN] Gold nanoparticles (AuNPs) were successfully synthesized by a facile chemical reduction method in the presence of the stabilizer polyvinylpyrrolidone and characterized by UV-vis spectroscopy and transmission electron microscopy. The gold nanoparticles were then incorporated onto the surface of a porous Ni electrode by simple addition of the nanoparticles suspension, followed by heat treatment at 350 degrees C for 1 h under nitrogen atmosphere. The modified electrode was morphologically characterized by field emission scanning electron microscopy. Then, the effect of the modification with Au nanoparticles was studied in the hydrogen evolution reaction (HER) by pseudo-steady-state polarization curves and electrochemical impedance spectroscopy (EIS), at different temperatures and compared with a pure porous Ni electrode. The modified electrode showed a clear improvement in its catalytic performance mainly due to the intrinsic catalytic activity of the Au nanoparticles. From the Tafel representations and the EIS, it was estimated that the HER on the electrode modified with AuNPs takes place by the Volmer-Heyrovsky mechanism.