The Solvent Role for the Decomposition of Paracetamol in Distilled and Drinking Water by Pure and Ag-Modified TiO2 Sol-Gel Powders

Albena Bachvarova-Nedelcheva; Reni Iordanova; Nina Kaneva

doi:10.3390/ma17081791

The Solvent Role for the Decomposition of Paracetamol in Distilled and Drinking Water by Pure and Ag-Modified TiO₂ Sol-Gel Powders

Materials (Basel). 2024 Apr 13;17(8):1791. doi: 10.3390/ma17081791.

Authors

Albena Bachvarova-Nedelcheva¹, Reni Iordanova¹, Nina Kaneva²

Affiliations

¹ Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bld. 11, 1113 Sofia, Bulgaria.
² Laboratory of Nanoparticle Science and Technology, Department of General and Inorganic Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier Blvd., 1164 Sofia, Bulgaria.

Abstract

In this study, pure TiO₂ gels were synthesized by applying the sol-gel method, using Ti(IV) butoxide with the addition of two different solvents, namely ethylene glycol (EG) and isopropanol (isop), with only air moisture present. It was established using XRD that the gel prepared with the addition of EG was amorphous even at 400 °C, while the other gel was amorphous up to 300 °C. It was found that TiO₂ (anatase) had a dominant crystalline phase during heating to 600 °C, while at 700 °C, TiO₂ (rutile) appeared. The as-obtained powdered materials were annealed at 500 °C and subsequently underwent photocatalytic tests with paracetamol. Additionally, the TiO₂ samples were modified with Ag⁺ co-catalysts (10^-2 M), using photofixation by UV illumination. The photocatalytic activity of the Ag-modified powders was also tested in the photodegradation of a commonly used paracetamol in aqueous solution under UV light illumination. The obtained data exhibited that the annealed samples had better photocatalytic efficiency and decomposed paracetamol faster in comparison to the non-annealed sol-gel powders. The highest degradation efficiency was observed for the TBT/isop/Ag material, with degradation efficiencies average values of 65.59% and 75.61% paracetamol achieved after the third cycle of photocatalytic treatment. The co-catalytically modified powders had higher photocatalytic efficiency in comparison to the pure nanosized powders. Moreover, the sol-gel powders of TBT/EG, TBT/EG/Ag (10^-2 M), TBT/isop, and TBT/isop/Ag (10^-2 M) demonstrated the ability to retain their photocatalytic activity even after three cycles of use, suggesting that they could find practical use in the treatment of pharmaceutical wastewater. The observed photocatalytic efficiency and positive impact of silver make the prepared powders a desirable choice for pharmaceutical drug degradation, helping to promote environmentally friendly and effective wastewater treatment technology.

Keywords: Ag/TiO2 powders; distilled and drinking water; paracetamol; photocatalytic degradation; sol–gel.

Grants and funding

N.K. is grateful for financial support from the Bulgarian NSF project KP-06-N59/11 (KП-06-H59/11).