Composite coatings of Ni Co LaNi5, prepared by electrolytic codepositon of Ni Co alloys and LaNi5 particles from a sulfamate electrolyte were investigated in view of its possible application as electrocatalytic materi...Composite coatings of Ni Co LaNi5, prepared by electrolytic codepositon of Ni Co alloys and LaNi5 particles from a sulfamate electrolyte were investigated in view of its possible application as electrocatalytic materials for the hydrogen evolution reaction(HER). The surface morphology and microstructure of Ni Co LaNi5 coatings were observed by means of SEM and XRD. Electrocatalytic efficiency was evaluated on the basis of electrochemical steady state Tafel polarization and electrochemical impedance spectroscopy technology in 1mol· L- 1 NaOH solution. The results were compared with Ni Co and Ni electrodes. The real electrochemical area was estimated by apparent double layer capacitances to account for the large difference in roughness factor of the three surfaces. The values obtained for the apparent energy of activation were 32.48kJ· mol- 1,46.29kJ· mol- 1 and 57.03kJ· mol- 1 for the HER on the Ni Co LaNi5, Ni Co and Ni electrodes, respectively. The composite coatings Ni Co LaNi5 is catalytically more active than Ni and Ni Co electrodes due to the increase in its real surface areas and the decrease in the apparent energy of activation caused by electrocatalytic synergistic effect of the Ni Co alloy and the rare earth compound on the electrode surface.展开更多
文摘Composite coatings of Ni Co LaNi5, prepared by electrolytic codepositon of Ni Co alloys and LaNi5 particles from a sulfamate electrolyte were investigated in view of its possible application as electrocatalytic materials for the hydrogen evolution reaction(HER). The surface morphology and microstructure of Ni Co LaNi5 coatings were observed by means of SEM and XRD. Electrocatalytic efficiency was evaluated on the basis of electrochemical steady state Tafel polarization and electrochemical impedance spectroscopy technology in 1mol· L- 1 NaOH solution. The results were compared with Ni Co and Ni electrodes. The real electrochemical area was estimated by apparent double layer capacitances to account for the large difference in roughness factor of the three surfaces. The values obtained for the apparent energy of activation were 32.48kJ· mol- 1,46.29kJ· mol- 1 and 57.03kJ· mol- 1 for the HER on the Ni Co LaNi5, Ni Co and Ni electrodes, respectively. The composite coatings Ni Co LaNi5 is catalytically more active than Ni and Ni Co electrodes due to the increase in its real surface areas and the decrease in the apparent energy of activation caused by electrocatalytic synergistic effect of the Ni Co alloy and the rare earth compound on the electrode surface.
