Characterization of Various Titanium-Dioxide-Based Catalysts Regarding Photocatalytic Mineralization of Carbamazepine also Combined with Ozonation
Gábor Kocsis,
Erzsébet Szabó-Bárdos,
Orsolya Fónagy,
Evelin Farsang,
Tatjána Juzsakova,
Miklós Jakab,
Péter Pekker,
Margit Kovács,
Ottó Horváth
Affiliations
Gábor Kocsis
Environmental and Inorganic Photochemistry Research Group, Center for Natural Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Erzsébet Szabó-Bárdos
Environmental and Inorganic Photochemistry Research Group, Center for Natural Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Orsolya Fónagy
Environmental and Inorganic Photochemistry Research Group, Center for Natural Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Evelin Farsang
Analytical Chemistry Research Group, Center for Natural Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Tatjána Juzsakova
Sustainability Solutions Research Lab, Research Center for Biochemical, Environmental and Chemical Engineering, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Miklós Jakab
Department of Materials Engineering, Research Center for Engineering Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Péter Pekker
Environmental Mineralogy Research Group, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Margit Kovács
Environmental and Inorganic Photochemistry Research Group, Center for Natural Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Ottó Horváth
Environmental and Inorganic Photochemistry Research Group, Center for Natural Sciences, University of Pannonia, P.O. Box 1158, H-8210 Veszprém, Hungary
Titanium-dioxide-based semiconductors proved to be appropriate for photocatalytic application to efficiently degrade emerging organic pollutants such as various herbicides, pesticides, and pharmaceuticals in waters of environmental importance. The characterization of various TiO2 catalysts, both bare and modified (Ag- and/or N-doped), by mechanochemical treatment was carried out in this work, regarding their structure, morphology, and photocatalytic activity. For the latter investigations, carbamazepine, an antidepressant, proved to be applicable and versatile. The photocatalytic behavior of the catalysts was studied under both UV and visible light. Besides the decomposition efficiency, monitoring the intermediates provided information on the degradation mechanisms. Mechanochemical treatment significantly increased the particle size (from 30 nm to 10 μm), causing a considerable (0.14 eV) decrease in the band gap. Depending on the irradiation wavelength and the catalyst, the activity orders differed, indicating that, in the mineralization processes of carbamazepine, the importance of the different oxidizing radicals considerably deviated, e.g., Ag-TiO2 2 2 2 ≈ N-Ag-TiO2 for O2•− and N-TiO2 ≈ Ag-TiO2 2 2 ≈ DP25-TiO2 for HO• generation under UV irradiation. Toxicity studies have shown that the resulting intermediates are more toxic than the starting drug molecule, so full mineralization is required. This could be realized by a synergistic combination of heterogeneous photocatalysis and ozonation.
