Photocatalytic performance of TiO2/zeolites under simulated solar light for removal of atenolol from aqueous solution

Removal of the beta-blocker atenolol from an aqueous solution was studied using TiO2/zeolites, prepared by a simple and cost-effective solid-state dispersion method. Synthetic zeolites 13X and ZSM-5 (Si/Al= 40) and natural zeolite clinoptilolite were used as one component of the hybrid materials, whereas TiO2 nanocrystals obtained from TiO2 nanotubes and P25 TiO2 nanoparticles were used as the other. The synthesized materials were characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transformed infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and scanning electron microscopy with energy-dispersive spectroscopy. The photocatalytic activity for the degradation of atenolol was investigated under simulated solar light. Additionally, the effect of initial pH on atenolol removal and the reusability of prepared catalysts were tested. The best loading of TiO2 was 20 wt% over all investigated zeolites. The degradation of atenolol followed the pseudo-first-order kinetics. The photocatalytic degradation of atenolol after 70 min of irradiation was similar to 50% for TiO2/13X materials, similar to 45% for clinoptilolite combined with P25 TiO2 and similar to 57% for clinoptilolite combined with TiO2 nanocrystals obtained from TiO2 nanotubes. The results showed the highest removal efficiency after 70 min of irradiation for ZSM-5 combined with P25 TiO2 (similar to 94%), followed by ZSM-5 combined with TiO(2 )nanocrystals obtained from TiO2 nanotubes (similar to 88%) at near-neutral pH (similar to 6.5). The total removal of atenolol from an aqueous solution for TiO2/ZSM-5 materials resulted from two processes: adsorption and photocatalytic degradation. The TiO2/ZSM-5 photocatalysts can be easily recovered and reused as their activity was preserved after four cycles.

Automated summary

In this study, TiO2/zeolites were used to remove the beta-blocker atenolol from an aqueous solution. The synthesized TiO2/ZSM-5 materials showed high photocatalytic activity under simulated solar light and were reusable.