Titanium dioxide (TiO2), one of the most frequently used materials in general, has emerged as an excellent photocatalytic material for environmental applications. In this review, principles and mechanisms of the photocatalytic activity of TiO2 have been analyzed. Structural and physical specificities of TiO2 nanoparticles, such as morphology, crystal structure, and electronic and optical properties, have been considered in the context of photocatalytic applications. A review of the influence of several factors, such as the type and dimensions of photocatalyst particles, pH of the solution, the influence of oxidants/electron acceptors, and light intensity on photocatalytic properties of TiO2, has been provided. Superhydrophilicity as an intrinsic property of the TiO2 surface was discussed through surface reconstruction on TiO2 during the reversible hydrophilic changes. Additionally, attention was paid to improving the photocatalytic properties of TiO2 particles through aggregation and agglomeration.

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Pharmaceuticals and pesticides are emerging contaminants problematic in the aquatic environment because of their adverse effects on aquatic life and humans. In order to remove them from water, photocatalysis is one of the most modern technologies to be used. First, newly synthesized photocatalysts were successfully prepared using a sol–gel method and characterized by different techniques (XRD, FTIR, UV/Vis, BET and SEM/EDX). The photocatalytic properties of TiO2, ZnO and MgO nanoparticles were examined according to their removal from water for two antibiotics (ciprofloxacin and ceftriaxone) and two herbicides (tembotrione and fluroxypyr) exposed to UV/simulated sunlight (SS). TiO2 proved to be the most efficient nanopowder under UV and SS. Addition of (NH4)2S2O8 led to the faster removal of both antibiotics and herbicide fluroxypyr. The main intermediates were separated and identified for the herbicides and antibiotic ciprofloxacin. Finally, the toxicity of each emerging pollutant mixture and formed intermediates was assessed on wheat germination and biomass production.

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In this work, the efficiency of direct photolytic and photocatalytic degradation of thiotriazinone, stable hydrolysis product of antibiotic ceftriaxone, was examined. The efficiency of photocatalytic degradation of 0.05 mmol/dm 3 thiotriazinone solution was investigated using commercially available TiO 2 Hombikat catalyst under simulated solar irradiation, as well as in the absence/presence of ammonium persulfate ((NH 4) 2 S 2 O 8) as electron acceptor. It was found that the optimal conditions for photocatalytic degradation of thiotriazinone were: catalyst loading 1.0 mg/cm 3 of TiO 2 Hombikat, electron acceptor 3 mmol/dm 3 of (NH 4) 2 S 2 O 8 solution, and pH 7.6. Under the stated conditions 76.0% of thiotriazinone was degradated after 60 min of irradiation. The kinetics of degradation was followed by UFLC-DAD technique.