Behaviour of coumarin in chloride bath: Relationship with coumarin influence on zinc electrodeposition

The behaviour of coumarin during zinc electrodeposition process has been studied. It was found that coumarin affects considerably the zinc deposition process and produces a deposit with a finer grain size. The glow discharge optical emission spectroscopy (GDOES) analysis revealed the presence of carbon in the deposits confirming the coumarin incorporation. The thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) analyses were also carried out in order to examine the cathodic reaction compounds of coumarin. The main coumarin cathodic compounds were the dihydrocoumarin and 3(2-hydroxyphenylpropionic acid). The influence of the two compounds on zinc electrodeposition was also studied and discussed.