In situ activation of a Ni catalyst with Mo ion for hydrogen evolution reaction in alkaline solution

In this study, the Ni catalyst has been activated during an hydrogen evolution reaction (HER) by adding Mo ions into the alkaline electrolyte. After dissolving different amounts of ammonium molybdate in 1M NaOH as an electrolyte, a Ni catalyst was used as the cathode for the HER. Then, a comparison between the hydrogen overpotential measured in the Ni catalyst with and without in situ activation hasbeen made. The in situ activation shows an improvement in electrocatalytic properties of the Ni catalyst for the hydrogen evolution reaction. In the other words, the impact increase of in situ activation of Mo ions on the Ni structure shows an extremely signi cant impact in improving the Ni catalyst activation during in situ activation. The values of the Tafel slope for the Ni catalyst without Mo is an average of about 141 mVdec-1, while this value is about 172 mVdec-1 using in situ activation with an activator Mo ion. As well as the values of overpotential for the Ni catalyst, are an average of about 625 mVwhen using in situ activation, these values are about 482 mV at the current density of 250 mAcm-2 (η250). In this study the electrochemical data was obtained from linear sweep voltammetry (LSV), the steadystate polarization Tafel curves, and electrochemical impedance spectroscopy (EIS).

کلیدواژه ها:

Hydrogen evolution reaction ، ، In situ activation ، ، Electrochemical impedance spectroscopy ، ، Electrocatalytic activity ،