In this study, unary ZnO, CuO, CdO, and ternary ZnO–CuO–CdO metal oxide thin film materials were fabricated using the SILAR procedure. The XRD spectra of the synthesized films show sharp and dominant diffraction lines, indicating the high crystallinity of both the unary and ternary composite films. The crystallite size values of unary ZnO, CuO, CdO, and ZnO–CuO–CdO ternary films were found to be 18.71 nm, 12.86 nm, 15.88 nm, and 21.96 nm, respectively. FESEM pictures exhibited that nanocomposites have spherical and nanorod-like hybrid morphology, and EDX showed that Cd has a higher content than Zn and Cu. The prepared samples’ FT-IR spectra in the wavenumber range of 500–4000 cm−1 revealed the existence of numerous vibrational modes. The optical bandgap values were found to be 1.47, 3.20, 2.21, and 2.51 eV for the CuO, ZnO, CdO, and ternary ZnO-CuO-CdO films, respectively. The photocatalytic efficiency of the ternary composites is higher than that of the unary metal oxides. The specific contact resistivity values were 780.83 kΩcm2, 213.33 kΩcm2 347.33 Ωcm2, and 1.97 kΩcm2 for ZnO, CuO, CdO, and ternary ZnO–CuO–CdO thin films, respectively. Our inventions provide advanced prompting for constructing new types of catalysts. The characterization results imply that the ternary nanocomposite can be used as a cost-effective alternative material for optoelectronic and photocatalytic implementations.