In this study, bismuth doped copper aluminate (CuAl2-xBixO4 x = 0, 0.01, 0.03, 0.05 and 0.10) nano particles were prepared via the solution combustion method and characterized by numerous procedures like powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, diffuse reflectance spectroscopy (DRS), scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDAX) and vibrating sample magnetometer (VSM). UV-Vis spectra exhibit low band gap energy ranging from 1.77 to 1.88 eV for the synthesized semiconductor oxide nanoparticles. The photocatalytic activity of copper aluminate and bismuth doped copper aluminate nanoparticles was studied by performing the decomposition of organic pollutants such as Methylene blue and Rhodamine-B under UV-light and visible light. It has been noticed from the results that the highest degradation was observed for Methylene blue dye with the bismuth doped copper aluminate (CABO3) nanoparticles compared to Rhoda-mine B. 99.71% degradation of Methylene blue was obtained within 60 min under UV-light irradiation and 99.90% within 60 min under visible light (H2O2) with 25 mg of catalyst. (C) 2017 Elsevier B.V. All rights reserved.