I imagine that you're liberating oxygen at the anode and hydrogen at the cathode.

The presence of nickel-boron is a red herring - as they're in a solution of water, right?

Hello Raja Babu ,

The answer to your question can be found in most standard Physical Chemistry textbooks, such as [1]. Section 21, of this book, talks about which of the competing reactions take place at the anode and cathode of your electrolysis cell; Section 22 deals with nonideal (irreversible) effects that change the applied voltage from its equilibrium value such as concentration polarization, and how to mitigate it; and Section 23 deals with nonideal (irreversible) effects that change the applied voltage from its equilibrium value such as overvoltage at the electrodes themselves.

Note, if you are trying to perform electroplating, the last thing you want is the evolution of gas at either electrode. Nickel should be deposited at the cathode (copper electrode), and the nickel of the anode should be going into solution to replace the nickel coming out of the solution at the cathode.

[1] Walter J. Moore; Physical Chemistry, Third Edition; Prentice-Hall, Inc.; 1962; pp.402-408, Section 21. Electrolysis: Decomposition Voltages, Section 22. Concentration Polarization, and Section 23. Overvoltage.

Regards,

Thomas Cuff

Hello Raja Babu ,

One other thing, in the title of your question you mention nickel sulfate, but in the body of the question you say NiB. The traditional nickel plating solution is nickel sulfate, nickel chloride, and boric acid (Watt's solution), see the following handbook: https://nickelinstitute.org/media/lxxh1zwr/2023-nickelplatinghandbooka5_printablepdf.pdf

Regards,

Thomas Cuff