Abstract
S-doped TiO&sub2; and hybrid MoS&sub2;/TiO&sub2; systems have been synthesized, via the sulfidation with H&sub2;S of the bare TiO&sub2; and of MoOx supported on TiO&sub2; systems, with the aim of enhancing the photocatalytic properties of TiO&sub2; for the degradation of carbamazepine, an anticonvulsant drug, whose residues and metabolites are usually inefficiently removed in wastewater treatment plants. The focus of this study is to find a relationship between the morphology/structure/surface properties and photoactivity. The full characterization of samples reveals the strong effects of the H&sub2;S action on the properties of TiO&sub2;, with the formation of defects at the surface, as shown by transmission electron microscopy (TEM) and infrared spectroscopy (IR), while also the optical properties are strongly affected by the sulfidation treatment, with changes in the electronic states of TiO&sub2;. Meanwhile, the formation of small and thin few-layer MoS&sub2; domains, decorating the TiO&sub2; surface, is evidenced by both high-resolution transmission electron microscopy (HRTEM) and UV-Vis/Raman spectroscopies, while Fourier-transform infrared (FTIR) spectra give insights into the nature of Ti and Mo surface sites. The most interesting findings of our research are the enhanced photoactivity of the MoS&sub2;/TiO&sub2; hybrid photocatalyst toward the carbamazepine mineralization. Surprisingly, the formation of hazardous compounds (i.e., acridine derivatives), usually obtained from carbamazepine, is precluded when treated with MoS&sub2;/TiO&sub2; systems.