Fabrication of ZnO-ZnS@polyaniline nanohybrid for enhanced photocatalytic degradation of 2-chlorophenol and microbial contaminants in wastewater

Abstract

In this work, a visible light active semiconductor photocatalyst ZnO-ZnS@polyaniline (ZnO-ZnS@Pani) nanocomposite was synthesized and its application was investigated for the photocatalytic degradation of organic and microbial contaminants in aqueous solution. The morphology and structural characteristics of the prepared materials were analysed using X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, Raman analysis and X-ray photoelectron spectroscopy. The photocatalytic activity of ZnO-ZnS@Pani was investigated for the degradation of 2-chlorophenol (2-CP) in synthetic wastewater under visible light irradiation as a function of contact time, pH and initial pollutant concentration. The highest 89% degradation of 2-CP was achieved at the pollutant concentration of 50 mg/L and 0.5 g/L catalyst dose. The efficient degradation was achieved due to the polyaniline in ZnO-ZnS@Pani nanocomposite which absorbs a wide range of visible light and inceases the eletron/hole separation. Moreover, the catalyst showed high stability and retained its photocatalytic activity up to the maximum level even after multiple reuses. Furthermore, ZnO-ZnS@Pani showed excellent antimicrobial action in sunlight against water born fecal E. coli, where 13.4% more effectiveness was observed as compared to ZnO-ZnS. These results revealed that ZnO-ZnS@Pani is an efficent visible light catalyst and can be used for the decontamination of wastewater.