Investigation of novel brightener acid blue 1 on copper electroplating coating

Fabricating nanocrystalline bright copper coatings is crucial for protection and decoration. A novel brightener organic anion acid blue 1 (AB1) was used to obtain nanocrystalline bright copper coatings. The suppressing effect of AB1 was verified and analyzed by electrochemical tests. Further insights into the effect mechanism of AB1 were investigated through density functional theory (DFT) calculations, molecular dynamics (MD) simulations and in situ Raman spectra. The phenomena of adsorption of AB1 on copper surface discovered by MD simulation and in situ Raman spectra, coupled with coordination interaction between − SO₃⁻ of AB1 and free Cu²⁺, synergistically inhibit the growth of copper coatings, resulting that compact and flat copper plating coatings were formed. The electroplating condition and copper coating morphology were studied, respectively. Bright flat copper coatings can be obtained with 100 to 200 mg/L AB1 under 5 A/dm². Besides, mass spectrum (MS) was used to evaluate the stability of AB1. The phase structure under the influence of AB1 concentration was studied using XRD. With the increase of AB1 concentration, the (111) surface is preferentially obtained. The average grain size of optimized copper coating, calculated according to Scherrer’s formula, is about 11 nm, indicating the acquisition of nanocrystalline copper plating coating. Finally, copper coatings obtained are of good corrosion resistance owing to low roughness and small grain size.