In this study, a combustion method as an efficient, easy, low-cost, and eco-friendly technique was used to synthesize nano-ZnO as a matrix with different yttrium doping ratios with different doping concentrations. Not only X-ray diffraction (XRD), but also scanning electron microscopy (SEM), and Fourier transformation Infrared spectroscopy (FT-IR) technique employed to characterize the structural and surface morphology of the Y2O3-ZnO nanocomposites. The obtained results supported ZnO's growth from crystalline to satisfactory nanoparticle structure by changing the yttrium doping concentrations inside ZnO nanoparticles. Moreover, UV-Vis diffuse reflectance spectroscopy, AC electrical conductivity, and current-voltage characteristics were considered to characterize the effects of yttrium doping on the energy bandgaps and electrical/dielectric properties and discussed the parameters of the ceramic varistors of the studied Y2O3-ZnO nano-complex oxides. The photocatalytic degradation efficiency of phenol, Methylene Blue, and Rhodamine B was investigated using all prepared Y2O3-ZnO nanostructured samples. As the yttrium doping ratios increased, the photocatalytic efficiency increased. After the addition of moderate Y3+ ions-doping, Further generation of hydroxyl radicals over ZnO. For Y2O3-ZnO (S5), the optimal photocatalyst is a degradation of 100 % of phenol, Methylene Blue, and Rhodamine B solutions compared to 80% of photocatalysis for ZnO stand alone. The prepared Y2O3-ZnO nanostructured materials are considered novel potential candidates in broad nano-applications ranging from biomedical and photocatalytic degradation for organic dyes and phenol to environmental and varistor applications.