Polymeric Floating Photocatalysts Based on PE/TiO2 Composites for the Removal of Organic Pollutants in Water

Polymeric floating photocatalysts based on polyethylene (PE)/TiO2 compositions were synthesized by in situ ethylene polymerization in the presence of a titanium–magnesium catalyst synthesized by the sequential deposition of a magnesium–aluminum complex and TiCl4 on commercial TiO2 P25. The optical band gap of the synthesized PE/TiO2 composites was shown to be 3.1–3.3 eV, which allowed for their use as photocatalysts for the utilization of solar light. The photocatalytic activity of the PE/TiO2 composites was studied for the degradation of methyl orange (MO) under irradiation with UV light (λmax = 384 nm). The composites containing 20–50 wt.% of PE were found to have an optimum combination between floatability and photocatalytic activity. The maximum photodegradation rate was observed at an MO concentration below 5 ppm. The polymeric PE/TiO2 floating photocatalysts could be used repeatedly, but the long-term exposure of the composites to UV radiation was accompanied by oxidation of the polymer.