In the present study, we describe an effective synthetic strategy of pure and heterostructured CeO₂/Y₂O₃ binary metal oxide nanostructures in distinct molar ratios (1:1; 1:2 & 2:1) in which sodium hydroxide act as a reducing agent under chemical precipitation assisted hydrothermal method (CPHM). Controlled shape and size of CeO₂/Y₂O₃ hierarchical nanostructures was achieved by using cerium nitrate and yttrium nitrate as a precursor. Synthesized nanostructure was fully analyzed by various techniques to detect its crystalline nature such as size, morphology; purity & optical activity is followed by the evaluation of its photocatalytic activity in the degradation of RhB dye. The crystalline structure was examined by X-ray diffraction (XRD), shows the cubic phase for both metal oxides in synthesized systems and found to be an efficient catalyst to generate reactive oxygen species (ROS) in presence of UV/Visible light, which tends to degrade various polyaromatic organic dyes into small fractions. Among all the heterostructured CeO₂/Y₂O₃ binary metal oxide nanostructures the Ce₂/Y1 sample shows the formation of hierarchical nanorods with particle diameter in the range of 8–50 nm. Due to their hierarchical one-dimensional nanostructures and increased surface areas, the CeO₂/Y₂O₃ hierarchical nanorods exhibit substantially higher photocatalytic performance than the pure CeO₂ and other mixed nanostructures in the degradation of RhB synthetic dye.