Visible light-responded S,N - codoped TiO2/SiO2 nanoparticles for photocatalytic degradation of paracetamol

The presence of pharmaceutical residues and their metabolits in water, even in low concentrations, is of significant concern due to their effects on aquatic environment. In this study, photocatalytic degradation of paracetamol (PA) has been investigated in aqueous solution over TiO2/SiO2 nanoparticles codoped with S and N. XRD, FE-SEM, EDX, FT-IR, DRS, PL were used to characterize the prepared photocatalysts. Experimental condition including pH, paracetamol concentration, photocatalyst concentration and irradiation time were optimized. The most degradation efficiency was obtained in acidic pH of 4 with study of photodegradation in pH amplitude of 2–12. The degradation efficiency was decreased in paracetamol concentrations above of 20 mg/L. The visible photocatalytic activity of S, N - codoped TiO 2/SiO2 was higher than that of TiO2/SiO2 and N or S doped TiO2/SiO2. The enhanced photocatalytic activity was attributed to the small crystallite size, the intense light absorbtion in visible region, narrow band gap and high seperation efficiency of photoinduced charge carriers. Furthermore, coupling of electrical current with photocatalytic process has proven to be effective in the degradation of PA aqueous solution clearly.

Keywords:

degradation , codoped TiO2 , paracetamol , nanoparticles