<p>The photocatalytic activity of metal oxides can be improved by doping and coupling with other semiconductors. In this work, pure SrTiO₃ and Ag@SrTiO₃ nanoparticles is successfully synthesis by ultrasonic assisted method to investigate the photocatalytic activity against ofloxacin antibiotic. Various analytical techniques are used to examine the morphology, crystallinity, bandgap and emission properties of prepared samples. The porous morphology of produced samples was shown by Field emission scanning electron microscopy (FE-SEM) analysis while the elemental mapping is studies using Energy-dispersive X-ray analysis. The structural analysis from X-ray diffraction (XRD) indicated cubic structural phase for both SrTiO₃ and Ag@SrTiO₃ samples. UV-Visible spectra absorption edge of the Ag@SrTiO₃ nanoparticles was slightly shifted towards longer wavelength due to increased electron-hole pair and separation compared to pure SrTiO₃. The photocatalytic activity was evaluated by the degradation of ofloxacin in presence of visible light irradiation. Under 75&#xa0;min visible light irradiation, Ag@SrTiO₃ photocatalyst decomposed 93% of the ofloxacin antibiotic, which was greater than that pure SiTiO₃ (84%). The enhanced photocatalytic efficiency of Ag@SrTiO₃ probably due to lowering bandgap and improvement of charge separation resulting from the effects of Ag doping. A density functional theory (DFT) simulation was performed to validate the experimental results and understand the process of photocatalytic degradation of the prepared SrTiO₃ and Ag@SrTiO₃ samples. The outstanding results using the Ag@SrTiO₃ catalyst shown its potential for the ofloxacin antibiotic degradation for the environmental applications.</p>