Flow synthesis of Ag3PO4/nAg nanoparticles and its photocatalytic and antimicrobial properties

Abstract

The multifunctional nAg-doped Ag3PO4 nanocomposites with a desirable content of silver nanoparticles 20–100 mg/g were synthesised in a flow microwave reactor. The surface and composition of Ag3PO4/nAg was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The effect of process parameters on the particle size of silver phosphate(V) and silver nanoparticles was investigated. Parameter analysis showed that the selection of microwave irradiation power, the ratio of tannic acid with reducing and stabilizing properties to silver ions, and the content of nanosilver addition to the salt resulted in Ag3PO4 nanoparticles with average crystallite size ranging from 56.92 to 82.13 nm with embedded silver nanoparticles ranging from 13.42 to 40.27 nm. Photocatalytic properties of the nanocomposite have been studied in the photodegradation process of methylene blue, achieving dye degradation efficiency exceeding 90 and 99% after 60 min in UV and visible light, respectively. Antimicrobial properties of the nanocomposite were also confirmed, both against E. coli (MIC = 500 mg/dm3) and S. aureus (MIC = 2000 mg/dm3) and fungi C. albicans (MIC = 1000 mg/dm3) which, based on nAg, MIC equals respectively 6, 24 and 12 mg/dm3. The deposition of silver nanoparticles preserves their high activity by preventing their uncontrolled release.