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

In this work, applications of nanohybrid composites based on titanium dioxide (TiO) 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/SWCNH composites were prepared by the solid-state interaction of the two chemical compounds. The increase in the SWCNH concentration in the TiO/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, which are attributed to the E(1) vibrational mode of TiO and the graphitic structure of SWCNHs; and (ii) a gradual increase in the IR band absorbance at 1735 cm because of the formation of new carboxylic groups on the SWCNHs' surface. The best photocatalytic properties were obtained for the TiO/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/SWCNH composite is a more efficient catalyst in AMOX photodegradation than TiO as a consequence of the SWCNHs' presence, which acts as a capture agent for the photogenerated electrons of TiO hindering the electron-hole recombination. The high stability of the TiO/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%.