In this study, samarium and aluminium codoped zinc oxide nanostructures were produced via a soft chemical route, and their structural, morphological, optical, and photocatalytic capabilities were investigated. X-ray diffraction (XRD) patterns and photoluminescence (PL) studies show that both undoped and Sm & Al codoped ZnO nanostructures have a hexagonal wurtzite crystal structure. The shape of the sample's hexagonal nanostructures, as seen in FESEM pictures, changes as the amount of Sm3+ doping increases. Sm3+ and Al2+ ions have been incorporated into ZnO, as seen by the EDX spectra. ZnO nanostructures were thoroughly studied to learn how Al2+ and Sm3+ doping affected their structure, shape, absorption, emission, and photocatalytic activity. The capacity to absorb visible light is enhanced by the incorporation of Sm3+ ions, which causes a red shift in the optical energy band gap from 2.5 to 3.2 eV. Based on the results of in-depth photocatalytic tests, it has been shown that Sm & Al codoped ZnO nanostructures exhibit the highest photodegradation efficiency for RhB dye for Sm0.04MAl0.04MZn0.92MO, i.e. 84%, when exposed to visible light. ZnO, when doped with a rare earth metal ion (Sm3+), displays enhanced photocatalytic efficiency and might have real-world uses. In this research, nanoscale photocatalysts, as manufactured, degrade RhB dye effectively as a photocatalyst