Photodeposition of silver on p-Cu2O/n-TiO2 nanocomposite applied to visible light degradation of 2,4-dichlorophenol in synthetic wastewater

This study presents a multicomponent photocatalytic system using simple impregnation-calcination of Cu2O particles followed by photodeposition of different amounts of Ag on TiO2 nanoparticles (TCA(a) samples) with high photocatalytic efficiency for 2,4-dichlorophenol (2,4-DCP) degradation under visible light. The obtained samples were characterized through X-ray diffraction, field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy, UV-Vis diffuse reflectance spectroscopy, N2 physisorption, and transmission electron microscopy techniques. The synthesized samples exhibited a high visible-light photocatalytic activity for 2,4-DCP degradation (50%) compared with pure TiO2 (28%), which is attributed to the synergetic effect of AgCl, Ag, and Cu2O on TiO2 nanoparticles. Furthermore, a dual Z-scheme charge transfer pathway is proposed and discussed for photocatalytic reactions taking place over the prepared photocatalysts. The degradation reactions follow first-order kinetics. Finally, reusing the best photocatalyst (TCA(1.2) did not result in any decline in its catalyst activity for 2,4-DCP degradation under visible light after four cycles.