Green synthesis of silver oxide nanoparticles using Trigonella foenum-graecum leaf extract and their characterization

The unique physical and chemical properties of silver nanoparticles (Ag NPs) of different sizes and shapes made their synthesis expedient. The most important method of NPs synthesis is the chemical process. However, the disadvantages of this method are the need for specific conditions such as high temperatures, to ensure formation and stability of NPs, as well as use of heavy aromatic solvents. Biosynthesis of NPs is considered advantageous over the traditional chemical approach. In this paper, the first report of the synthesis of silver oxide (AgO) NPs using Trigonella foenum-graecum leaf extract as a reducing agent is presented. The NPs were characterized by X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TA/DTA), UV, photoluminescence, SEM, EDX and high resolution transmission electron microscopy (HRTEM). The XRD confirmed the formation of high -purity AgO fine crystals. The average crystal size ranged from 27 to 32 nm as was revealed by HRTEM. From the Tauc plot, the optical band gap of the AgO crystals of 3.3 eV was determined. Thermal analysis provided the optimum temperature for calcination of the AgO NPs to be 400 degrees C.