Syntehsis of Novel Zno/Tio2 Nanopowder Catalyst for Photodegradation of Pharmaceutically Active Water Pollutants
ZnO/TiO2 mixed powder photocatalyst was prepared using a simple, inexpensive, three- step mechanochemical solid-state method. Starting precursors (ZnO and TiO2 Sigma Aldrich, purity 99.9%) were ground in an agate mortar for 10 min in molar ratio 2:1, annealed at 700°C in air for two hours and ground again for 10 min. The phase composition, crystalline structure and morphology of the obtained nanopowder were studied using a variety of techniques. For that purpose, X-ray diffraction (XRD) was carried out using Philips PW1050 instrument, with CuKα1,2 radiation and a step scan mode of 0.02°/2s in angular range 2θ=15–100°. Scanning electron microscopy, BET and Raman scattering were also employed to provide information on the morphology and optical properties of the materials. The photocatalytic decomposition of Naproxen, one of most frequently detected pharmaceutical residue in water bodies, was carried out at room temperature (ca. 293 K) in aqueous solution upon UV illumination in batch mode. The kinetics of the Naproxen photodegradation in the presence of the obtained mixed catalyst was monitored using the HPLC (high performance liquid chromatograph) with diode array detector (Agilent 1260 series). Removal efficacy by photocatalytic degradation of Naproxen after 60 minutes was 99%. Measurements also showed that direct photocatalysis and adsorption are insignificant, proving that the overall photodegradation effect is due to the presence of the newly synthesized ZnO/TiO2 nanopowder.
Keywords- Nanopowder, Photocatalyst, Naproxen