This study describes a straightforward and affordable photolysis approach for the large-scale production of barium oxide nanoparticles (BaO-NPs). BaO-NPs were synthesized Using the UV-Irradiation Technique. The structural, morphological, compositional, and optical characteristics were studied by XRD, TEM, SEM, EDX and PL. the The BaO-NPs crystallite size was determined to be 14.6 nm. the morphology of BaO nanoparticles which demonstrated the existence of nanoparticles in the produced materials. and predicted bandgap of the nanoparticles was determined to be 3.26 eV by photoluminescence spectroscopy. BaO NPS that have been produced exhibit desirable adsorbent behavior for cibacron blue dye in their aqueous solutions. the effects of contact time, adsorbent mass, temperature, and starting cibacron blue dye concentration were investigated. The dye isotherm adsorption demonstrated good Freundlich agreement. The ∆H, ∆S, and ∆G parameters were calculated using a thermodynamic Van't Hoff equation, and the results were 9.69701 kJ/mol, 0.813 kJ/mol K, and 9.403 kJ/mol, respectively. Additionally, the kinetic investigation revealed that the adsorption exhibited pseudo-second-order behavior.