Effect of Sodium Hypophosphite Content in the Electroplating Bath on the Electrochemical Properties of Ni-P Alloy Coatings

Abstract:

Porous Ni-P alloy coatings were prepared by galvanostatic electrodeposition at the deposition current density of j_dep = -250 mA cm^-2 from the nickel plating bath of the Watts type containing different content of sodium hypophosphite. Investigations of hydrogen evolution reaction (HER) were carried out in 5 M KOH solution at room temperature. Ac impedance behavior of the electrodes was described using electrical equivalent circuits containing two constant-phase elements (two-CPEs electrode model). The results obtained from the EIS and steady-state measurements allowed to determine the Volmer-Heyrovský mechanism and kinetics of the HER. It was found that for the Ni-P alloy coatings deposited from the galvanic baths after addition of sodium hypophosphite in the amount of 5, 10, 20 and 30 g dm^-3, the decrease in their catalytic activity towards the HER is observed due to diminishing of intrinsic activity of the electrodes.

• Periodical: Solid State Phenomena (Volume 228)
• Pages: 246-251
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.228.246
• Online since: March 2015
• Authors: Magdalena Popczyk*, B. Łosiewicz
• Keywords: Electroplating, Hydrogen Evolution Reaction, Ni-P Alloy Coating, Sodium Hypophosphite

References

[1] I. Arul Raj, K.I. Vasu: J. Appl. Electrochem. Vol. 22 (1992), p.471.

[2] Y. Choquette, L. Brossard, H. Mènard: Int. J. Hydrogen Energ. Vol. 15 (1990), p.551.

[3] J. Carvalho, G. Tremiliosi-Filho, L.A. Avaca, E.R. Gonzalez: Int. J. Hydrogen Energ. Vol. 14 (1989), p.161.

[4] M.J. De Giz, G. Tremiliosi-Filho, E.R. Gonzalez, S. Srinivasan, A.J. Appleby: Int. J. Hydrogen Energ. Vol. 20 (1995), p.423.

DOI: 10.1016/0360-3199(94)00068-b

[5] H-B. Lee, C-H. Hsu, D-S. Wuu: J. New Mat. Elect. Syst. Vol. 14 ( 4) (2011), p.237.

[6] B. Łosiewicz, A. Budniok, E. Rówiński, E. Łągiewka, A. Lasia: Int. J. Hydrogen Energ. Vol. 29 (2004), p.145.

[7] B. Łosiewicz, A. Budniok, A. Lasia, E. Łągiewka: Pol. J. Chem. Vol. 78 (2004), p.1457.

[8] B. Łosiewicz, A. Budniok, E. Rówiński, E. Łągiewka, A. Lasia: J. Appl. Electrochem. Vol. 34 (2004), p.507.