Nanohybrid Composites Based on TiO(2) and Single-Walled Carbon Nanohorns as Promising Catalysts for Photodegradation of Amoxicillin

In this work, applications of nanohybrid composites based on titanium dioxide (TiO(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(2)/SWCNH composites were prepared by the solid-state interaction of the two chemical compounds. The increase in the SWCNH concentration in the TiO(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(−1), which are attributed to the E(g)(1) vibrational mode of TiO(2) and the graphitic structure of SWCNHs; and (ii) a gradual increase in the IR band absorbance at 1735 cm(−1) because of the formation of new carboxylic groups on the SWCNHs’ surface. The best photocatalytic properties were obtained for the TiO(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(2)/SWCNH composite is a more efficient catalyst in AMOX photodegradation than TiO(2) as a consequence of the SWCNHs’ presence, which acts as a capture agent for the photogenerated electrons of TiO(2) hindering the electron–hole recombination. The high stability of the TiO(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%.