Corrosion inhibition of copper by eco-engineered transition metal chalcogenides: An integrated experimental, and hybrid machine learning prediction

In this work, the anticorrosion mechanism of a hybrid transition metal chalcogenides was investigated for copper in simulated marine environment. The hybrid composite material integrates transition metals and selenides within a tailored host matrix to explore the synergistic effects in surface adsorption, and barrier formation on the copper surface. The hybrid chalcogenide composite was designed via hydrothermal method and a comprehensive physicochemical characterization such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) confirmed the formation of the transition metal chalcogenide phase. The electrochemical techniques via Potentiodynamic polarization (PDP), and electrochemical impedance measurements demonstrated that the hybrid transition metal chalcogenides significantly reduced corrosion current densities and increased the charge transfer resistance for copper up to 90% at 100 ppm NiCo₂S₄ with a cathodic inhibition mechanism. The surface characterization after immersion indicated the formation of a compact protective film that impede the ingress of chloride attack. Furthermore, to elucidate into the inhibition mechanism, a multifaceted approach integrating computational studies and machine learning (ML) model was used. The ML regression models trained on DFT and MD descriptors successfully reproduced adsorption energy trends, with Ridge and ElasticNet models showing strong predictive capability with high R² values, and low RMSE/MAE errors highlighting the role of heteroatom (sulfur) coordination and electron donation in stabilizing the inhibitor film. Thus, the multifaceted approach provides a holistic, multi-scale approach that not only clarifies the inhibition mechanism but also unveil the rational design of next-generation corrosion inhibitors.