Enhanced photocatalytic degradation of 2,4-dichlorophenol in water solution using Sr-doped ZnAl2O4 nanoparticles

ZnAl2O4 and Sr-doped ZnAl2O4 nanoparticles were synthesized by co-precipitation using ammonia as precipitating agent, followed by thermal treatment at 700°C. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and the Brunauer-Emmett-Teller (BET) were employed to clarify the structure and morphology of the samples. In addition, the presence of Sr in Sr-doped ZnAl2O4 NPs was further evidenced from energy-dispersive X-ray analysis (EDX). The Photocatalytic activity of ZnAl2O4 and Sr-doped ZnAl2O4 nanoparticles were evaluated in the photo-catalytic degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous media under the UV irradiation technique. The effect of various parameters, including catalyst dosage, 2,4-DCP concentration, pH, and temperature, on the degradation of 2,4-DCP was investigated. With 0.6 wt% Sr doped ZnAl2O4 samples after 60 min irradiation, 100% of 2,4-DCP photodegradation was observed in acidic conditions, while with undoped ZnAl2O4 samples only 67% 2,4-DCP was removed upon UV irradiation for 200 min. The reusability of the catalyst was examined under optimized conditions. The results demonstrate that Sr-doped ZnAl2O4 nanoparticles exhibit considerably high catalytic stability with more than 90% degradation after the third catalytic cycle.