In this work, composite coatings were developed on Cu–Ni alloy substratesthrough the electrochemical polymerization of 3-amino-5-mercapto-1,2,4-triazole (3-AMTa), followed by the incorporation of inorganic oxides such as TiO₂, ZnO, CeO₂, and SiO₂ using a cyclic voltammetric deposition method. The corrosion protection behaviour of the resulting coatings in a neutral medium was evaluated using electrochemical impedance spectroscopy and Tafel polarization analysis. Structural features were characterized by Fourier-transform infrared spectroscopy and X-ray diffraction, while scanning electron microscopy, energy dispersive X-ray spectroscopyand atomic force microscopy provided detailed insights into surface morphology, elements exist and topography of the prepared polymeric matrix, respectively. Electrochemical studies revealed that the incorporation of metal oxides into the Poly-3-AMTa matrix significantly lowered the corrosion current density and improved the inhibition efficiency compared to the uncoated Cu–Ni alloy. The inhibition efficiency followed the sequence: TiO₂ (96.8%) > ZnO (93.2%) > CeO₂ (89.3%) > SiO₂ (80.6%) > Poly-3-AMTa (73.2%), demonstrating the superior corrosion resistance imparted by TiO₂. AFM observations showed that the TiO₂-based composite coatings possessed the smoothest and most compact surface, while the addition of metal oxides in generaly enhanced film uniformity, reduced surface defects, and modified surface roughness. Scanning electron microscopyimages further confirmed that the formation of dense, adherent, and defect-free coatings, particularly in theTiO₂-modified coatings. The X-ray photoelectron spectroscopy techniques demonstrated the elements core-level spectra of C 1s, N 1s, S 2p, Ti 2p, Ni 2p and Cu 2p. Thiscould be dueto the back donation of TiO2which bindsto the poly-3-AMTa molecule.The results indicated that embedding metal oxides within the Poly-3-AMTa framework markedly improved the barrier protection,surface integrity, and electrochemical stability of Cu–Ni alloy coatings, with TiO₂ emerging as the most effective oxide additive for enhanced corrosion resistance in neutral and aggressive environments.