Modification of clinoptilolite nano-particles with iron oxide: Increased composite catalytic activity for photodegradation of cotrimaxazole in aqueous suspension

Photocatalytic degradation of a pharmaceutical cotrimaxazole capsule in aqueous solution was studied using Iron oxide (IO) supported onto clinoptilolite nano-particles (NCP) and Hg-lamp as radiation source. The ball mill prepared NCP was ion exchanged in Ferrous chloride aqueous solution (0.3 M) for 24 h and then calcined at 450 °C for 12 h for preparation of the IO–NCP catalyst. The raw and modified samples were characterized by X-ray diffraction (XRD), Fourier transformation infrared (FT-IR), UV–vis diffuse reflectance spectroscopy (DRS) and Transmission electron microscope (TEM). Degradation extent of the pollutant was estimated by UV–vis spectroscopy and confirmed by COD and HPLC. Experimental parameters significantly affected the efficiency of the process and their optimum values were estimated as: 0.5 g L−1 of the photocatalyst, 50 folds diluted of the original solution (one capsule/100 mL) and pH 4.3. The proposed catalyst retained above 60% of its initial activity after 3 sequential re-using runs.