Influence of nicotinic acid additive on the electrodeposition of nickel from aqueous solution

In nickel-plating aqueous baths, both organic and inorganic additives are employed to enhance surface finish, reduce roughness, and achieve a uniform morphology of the coatings. This study investigates how four different concentrations of nicotinic acid (NA) additive, combined with a fixed concentration of boric acid, influence nickel electrodeposition in an aqueous solution, with minimal effect on the speciation of Ni(II) clusters. NA inhibits the Ni(II) reduction process even at a low concentration of 0.01 M, resulting in negligible changes in behavior compared to the additive-free environment. A higher concentration of 0.06 M NA is required to achieve a high-quality surface. The study demonstrates that the inclusion of NA significantly alters the electrochemical behavior relative to the additive-free regime. For instance, the use of both additive systems leads to coatings with relatively high microhardness and brighter, smoother deposits.