Green-photodegradation of model pharmaceutical contaminations over biogenic Fe3O4/Au nanocomposite and antimicrobial activity.

A simple biogenic approach for synthesis of Fe 3 O 4 /Au nanocomposite with 31 nm size using aqueous extract of Carum carvi L. seeds has been reported. Phytochemicals of Carum carvi L. seeds extract play three roles, including reducing, capping, and stabilizing agents during the nanocomposite fabrication process. Resulting nanocomposite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, differential reflectance spectroscopy, vibrating-sample magnetometer, energy-dispersive X-ray spectroscopy and X-ray elemental mapping. Differential reflectance spectroscopy investigated optical property and absorption spectra display a sharp absorption agreeing to a bandgap of 1.6 eV. Photocatalytic activity of biogenic Fe 3 O 4 /Au nanocomposite has been investigated for degradation of imatinib and imipenem drugs under UV and visible light irradiation, due to pharmaceuticals have shown to be recalcitrant in wastewater and conventional wastewater treatments do not remove them, often. Degradation efficiency of imatinib, and imipenem are about 92% and 96% after 1200 s exposure UV light and about 82% and 84% after 3600s exposure visible light in the concentration of 10 ppm drugs. Also, antimicrobial activity of biogenic Fe 3 O 4 /Au nanocomposite was investigated on three human pathogens and best result can see in 25 mg/mL of nanocomposite versuse Bacillus subtilis that inhibition zone is about 27 mm. Design of nanocomposites capable of simultaneously removing pharmaceutical and microbial contaminations is important in environments such as hospitals wastewater treatment. • Biogenic Fe 3 O 4 /Au nanocomposite photocatalyst prepared at room temperature. • Nanocomposite showed excellent photocatalyst activity in UV and Visible light. • Photocatalytic mechanism of biogenic Fe 3 O 4 /Au nanocomposite proposed. • Biogenic Fe 3 O 4 /Au nanocomposite showed superior antimicrobial activity. [ABSTRACT FROM AUTHOR]