Pyrolysis preparation of poly-γ-glutamic acid derived amorphous carbon nitride for supporting Ag and γ-Fe_2O_3 nanocomposites with catalytic and antibacterial activity

摘要

Nanocomposites composed of Ag and gamma-Fe2O3 nanoparticles within poly-gamma-glutamic acid (gamma-PGA) derived amorphous carbon nitride (a-CN) films (Ag + gamma-Fe2O3@a-CN) were synthesized by a one-step facile pyrolysis strategy. Transmission electron microscopy analysis shows that Ag and gamma-Fe2O3 nanoparticles were obtained in situ and homogeneously dispersed on the a-CN matrix. The average size of nanoparticles was 8.1 nm. The presence of gamma-Fe2O3, Ag, and a-CN in the nanocomposite was confirmed by X-ray diffraction analysis, UV-visible absorption spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Ag + gamma-Fe2O3@a-CN catalyzed the degradation of methyl orange. This catalyst was also recycled ten times by magnetic separation without any loss in efficiency. Ag + gamma-Fe2O3 @a-CN exhibited strong antibacterial activity against E. coli and S. aureus. It also exhibited excellent antibacterial activity even after 20 times magnetic recycling. This indicates that this is a promising recyclable antibacterial and catalyst for environmental applications.