Chelator-engineered nano-electroless copper coatings on epoxides: surface and electrochemical properties

This investigation explores the electroless deposition of copper nanoparticles onto epoxy substrates using glyoxylic acid as the reducing agent. The deposition process was conducted under alkaline conditions, with the pH precisely maintained at 11.0 ± 0.25 using potassium hydroxide. Two distinct methanesulphonate bath formulations were employed with glucose and fructose as chelators to enhance complexation efficiency. Azole-based stabilizers, Aminopyrazole and Tolytriazole were introduced to fine-tune bath parameters and improve deposition control. Comprehensive characterization of the resulting copper coatings was performed using scanning electron microscope-energy dispersive X-ray analysis (SEM-EDAX), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), tafel analysis, and electrochemical impedance spectroscopy (EIS). The bath containing glucose as the chelator demonstrated superior stability and yielded high-quality, uniform copper deposits with enhanced surface and electrochemical properties. The novelty of this work is the addition of a chelating agent to the electroless copper deposition process on polymeric substrates, which offers a more sustainable and environmentally friendly method while providing better adhesion, refined grain morphology, and improved electrochemical performance when compared to traditional surface treatments.