Nanohybrid Composites Based on TiO[sub.2] and Single-Walled Carbon Nanohorns as Promising Catalysts for Photodegradation of Amoxicillin

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 19
• Main Authors: Cercel, Radu, Androne, Andreea, Florica, Cristina Stefania, Lőrinczi, Adam, Serbschi, Constantin, Baibarac, Mihaela
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.10.2023
• Subjects: Amoxicillin; Catalysts; Cloxacillin; Graphene
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28196958

In this work, applications of nanohybrid composites based on titanium dioxide (TiO[sub.2]) with anatase crystallin phase and single-walled carbon nanohorns (SWCNHs) as promising catalysts for the photodegradation of amoxicillin (AMOX) are reported. In this order, TiO[sub.2]/SWCNH composites were prepared by the solid-state interaction of the two chemical compounds. The increase in the SWCNH concentration in the TiO[sub.2]/SWCNH composite mass, from 1 wt.% to 5 wt.% and 10 wt.% induces (i) a change in the relative intensity ratio of the Raman lines located at 145 and 1595 cm[sup.−1], which are attributed to the E[sub.g](1) vibrational mode of TiO[sub.2] and the graphitic structure of SWCNHs; and (ii) a gradual increase in the IR band absorbance at 1735 cm[sup.−1] because of the formation of new carboxylic groups on the SWCNHs’ surface. The best photocatalytic properties were obtained for the TiO[sub.2]/SWCNH composite with a SWCNH concentration of 5 wt.%, when approx. 92.4% of AMOX removal was achieved after 90 min of UV irradiation. The TiO[sub.2]/SWCNH composite is a more efficient catalyst in AMOX photodegradation than TiO[sub.2] as a consequence of the SWCNHs’ presence, which acts as a capture agent for the photogenerated electrons of TiO[sub.2] hindering the electron–hole recombination. The high stability of the TiO[sub.2]/SWCNH composite with a SWCNH concentration of 5 wt.% is proved by the reusing of the catalyst in six photodegradation cycles of the 98.5 μM AMOX solution, when the efficiency decreases from 92.4% up to 78%.