Photocatalytic activity of TiO2 mechanochemically modified with carbon and/or thiourea under UV and visible irradiation in the destruction of Safranine T and Rifampicinum

Titanium dioxide (anatase) powders mechanochemically modified with carbon and/or thiourea were obtained. X-ray powder diffraction, scanning electron microscopy with an integrated system for electron microprobe analysis, transmission electron microscopy, Brunauer-Emmett-Teller surface area analysis, X-ray photoelectron spectroscopy, infrared and ultraviolet-visible spectroscopies were applied for the powders characterization. Mechanochemical modification with thiourea and/or carbon with carbon and/or thiourea led to a decrease of the particle size from 21 to 13 nm and formation of oblong rice-like particles. The presence of a hysteresis loop in the nitrogen ad(de)sorption isotherms for the synthesized samples proved their mesoporous structure. The features of the XPS spectra in all samples can be attributed to the fine-structure peculiarities associated with titanium, oxygen, and carbon atoms and, in the case of modification with thiourea, additionally, to sulfur and nitrogen. Photocatalytic activity of the samples was investigated in the photodestruction of Safranine T and Rifampicinum. The modified samples showed higher photocatalytic activity in both reactions compared to unmodified anatase under UV irradiation and demonstrated activity under visible light. The reusability of the powders was investigated.