A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum（ATG）.A fast,simple,and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape fro...A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum（ATG）.A fast,simple,and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape from the silver nitrate solution.Shallot as a reducing agent and apricot tree gum（ATG） as a stabilizer and a capping agent were utilized to reduce and form silver ions into silver atoms with needle and particle shape.Moreover,high crystalline structures of silver nanoparticles（AgNPs） with diameters of 8-20 nm and silver nanoneedles with average diameters of 50-60 nm and lengths of 5-10 μm were consequently synthesized by shallot and the mixture of shallot and ATG.A self-assembly mechanism was proposed to indicate the formation of needle-like structures of spherical Ag NPs via carbon chains of ATG.The results indicate that the presence of ATG with shallot can transfer the reduced Ag NPs into the silver nanoneedle.The findings were characterized using X-ray diffraction（XRD）,ultra violet visible（UV-Vis） spectrometry,field emission scanning electron microscopy（FESEM）,and transmission electron microscopy（TEM） techniques.展开更多
Synthesis of Ag nanoparticles dispersed in germanium dioxide （GeO2） matrix was performed via sol-gel route. Analysis of the powder X-ray diffraction （XRD） pattern shows fcc cubic unit cell of Ag with lattice param...Synthesis of Ag nanoparticles dispersed in germanium dioxide （GeO2） matrix was performed via sol-gel route. Analysis of the powder X-ray diffraction （XRD） pattern shows fcc cubic unit cell of Ag with lattice parameters： a = 4.0884 A, space group Fm-3m. Energy dispersive analysis of X-rays （EDAX） results show the presence of only GeO2 and Ag in the sample. The average crystallite sizes of Ag particles determined by Scherrer＇s relation are found to be i 8-47 nm. Observed sharp electron paramagnetic resonance （EPR） lineshapes at 8, 70 and 300 K with g-values of 2.004, 2.004, and 2.004, respectively, show that the Ag （5s~） electrons are localized in the Ag nanoparticles. The calculated value of the magnetic susceptibility is 1.014~ 10-5 emu/gG from the observed magnetic moments data at 300 K, which shows fairly strong paramagnetic nature of the material. Refinement of Ag crystal structure in space group Fm-3m with Ag atoms in 4（a） position shows the agreement bond length as 2.8909 ,＆. Calculated density of states below Fermi factors Rp= 67.22%, Rwp= 75.7%, Rexp= 0.06%, Z = 4 and Ag-Ag energy, EF, from -2 to -8 eV are due to valence d orbitals of Ag.展开更多
基金supported by the international doctoral fellowship (IDF) scheme from Universiti Teknologi Malaysia
文摘A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum（ATG）.A fast,simple,and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape from the silver nitrate solution.Shallot as a reducing agent and apricot tree gum（ATG） as a stabilizer and a capping agent were utilized to reduce and form silver ions into silver atoms with needle and particle shape.Moreover,high crystalline structures of silver nanoparticles（AgNPs） with diameters of 8-20 nm and silver nanoneedles with average diameters of 50-60 nm and lengths of 5-10 μm were consequently synthesized by shallot and the mixture of shallot and ATG.A self-assembly mechanism was proposed to indicate the formation of needle-like structures of spherical Ag NPs via carbon chains of ATG.The results indicate that the presence of ATG with shallot can transfer the reduced Ag NPs into the silver nanoneedle.The findings were characterized using X-ray diffraction（XRD）,ultra violet visible（UV-Vis） spectrometry,field emission scanning electron microscopy（FESEM）,and transmission electron microscopy（TEM） techniques.
文摘Synthesis of Ag nanoparticles dispersed in germanium dioxide （GeO2） matrix was performed via sol-gel route. Analysis of the powder X-ray diffraction （XRD） pattern shows fcc cubic unit cell of Ag with lattice parameters： a = 4.0884 A, space group Fm-3m. Energy dispersive analysis of X-rays （EDAX） results show the presence of only GeO2 and Ag in the sample. The average crystallite sizes of Ag particles determined by Scherrer＇s relation are found to be i 8-47 nm. Observed sharp electron paramagnetic resonance （EPR） lineshapes at 8, 70 and 300 K with g-values of 2.004, 2.004, and 2.004, respectively, show that the Ag （5s~） electrons are localized in the Ag nanoparticles. The calculated value of the magnetic susceptibility is 1.014~ 10-5 emu/gG from the observed magnetic moments data at 300 K, which shows fairly strong paramagnetic nature of the material. Refinement of Ag crystal structure in space group Fm-3m with Ag atoms in 4（a） position shows the agreement bond length as 2.8909 ,＆. Calculated density of states below Fermi factors Rp= 67.22%, Rwp= 75.7%, Rexp= 0.06%, Z = 4 and Ag-Ag energy, EF, from -2 to -8 eV are due to valence d orbitals of Ag.
