graphene oxide/hydroxyapatite/silver (rgo/hap/ag) nanocomposite: synthesis, characterization, catalytic and antibacterial activity

In this paper, a novel ternary nanocomposite namely reduced graphene oxide/hydroxyapatite/silver (rgo/ hap/ag) was prepared by a simple hydrothermal method using graphene oxide nanosheets, ca(no3)2, (nh4)2hpo4, and agno3 as starting materials. the as-prepared nanocomposite was characterized by using various photophysical techniques including fourier transform infrared spectroscopy (ft-ir), raman spectroscopy, x-ray diffraction (xrd), ultraviolet-visible (uv-vis) spectroscopy, transmission electron microscopy (tem), scanning electron microscopy (sem), and energy dispersive x-ray analysis (edx). additionally, the antibacterial and catalytic activities of the nanocomposite were evaluated. the results showed that the rgo/hap/ag nanocomposite exhibited high performance in the reduction of toxic nitro compounds (4-nitrophenol, 2-nitrophenol, 4-nitroaniline, and 2-nitroaniline) into the less toxic corresponding amines using nabh4 within 21-42 min with a rate constant equal to 0.1646, 0.0898, 0.1071 and 0.2 min-1, respectively. moreover, the rgo/hap/ag nanocomposite could be separated from the reaction mixture due to its heterogeneous nature and reused without any change in structure. in addition, the antibacterial activity of the rgo/hap/ag nanocomposite by disk diffusion method was evaluated against gram-positive bacteria (bacillus cereus and staphylococcus aureus) and gram-negative bacteria (escherichia coli and klebsiella pneumonia). the results showed that this novel ternary nanocomposite has good antibacterial activity against gram-positive bacteria.