Efficient photocatalytic degradation of furosemide by a novel sonoprecipited ZnO over ion exchanged clinoptilolite nanorods

This work presents, a detailed investigation for photocatalytic degradation of the drug furosemide (FRS) using zinc oxide (ZnO) supported on ion-exchanged natural zeolite clinoptilolite (ICLT). The ZnO/ICLT nanophotocatalysts were effectively synthesized by sonoprecipitation method which enhanced the photocatalytic performance by increasing the surface area and decreasing the particle size, compared to conventional precipitated samples. Microstructure and optical properties of prepared catalysts were characterized using XRD, XRF, FESEM, surface particle size distribution, TEM, EDX, BET, BJH, DRS and UV-visible spectroscopy techniques. XRD data confirmed the formation of ZnO. FESEM images revealed small particle size of active metals and low numbers of agglomerations which is in accordance with EDX dot mapping results. The average particle size of ZnO in ZnO(15%)/ICLT whit sonication was 20.5 nm whereas it was 34.8 nm without sonication. Moreover, the literature review indicated that ultrasound irradiation during the precipitation of samples has not been studied yet which highlight the importance of evaluating this nanophotocatalyst for wastewater treatment applications. The maximum degradation rate was observed for 15 wt% ZnO among various contents of ZnO used in synthesized nanocomposites. The influence of key operational parameters such as catalyst dosage, initial FRS concentration and pH on the photocatalytic degradation was assessed. Total organic carbon mineralization rate of FRS solution and energy consumption were also assessed to compare the ability of different processes in FRS degradation. Results showed also excellent reusability of fabricated nanophotocatalyst. Finally a plausible degradation mechanism for photocatalytic degradation of FRS was proposed.