Nanoparticle energy dispersive spectroscopy

Particle composition is far more difficult to evaluate. Bulk elemental analysis [atomic absorption spectroscopy (AA) or inductively coupled plasma mass spectrometry (ICP-MS) are most common for metals] is useful in confirming the overall bimetallic composition of the sample, but provides no information regarding individual particles. Microscopy techniques, particularly Energy Dispersive Spectroscopy (EDS), has supported the assertion that bimetallic DENs are bimetallic nanoparticles, rather than a physical mixture of monometallics [16]. Provided the particle density is low... 

Synthesis of alloyed silver-palladium bimetallic nanoparticles was achieved by /-irradiation of aqueous solutions containing a mixture of Ag and Pd metal ions using different Ag/Pd ratios. The synthesis of alloys implies the simultaneous radio-induced reduction of silver and palladium ions. The nanoparticles were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The Ag-Pd nanoparticles display a face-centered cubic (fee) crystalline structure. The lattice parameter was measured for several Ag/Pd ratios and was found to closely follow Vegard s law, which indicates the formation of homogeneous alloys. In order to avoid the simultaneous reduction of silver and palladium ions which leads to alloyed bimetallic nanoparticles. 

The novel SERS-active substrates were prepared by electrodeposition of Ag nanoparticles in the MWCNTs-based nanocomposites. The formation of Ag-MWCNTs nanocomposite was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The application of the Ag-MWCNTs nanocomposite in SERS was investigated by using rhodamine 6G (R6G). The present methodology demonstrates that the Ag-MWCNTs nanocomposite is suitable for SERS sensor. 

To identify nanoparticles there are several analytical techniques, including crystalline nature, surface plasmon resonance, size, shape, stability, nature, etc., which was done by various analytical instruments, such as UV-visible spectroscopy, X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis, zeta potential, etc. These are mostly used for analysis of synthesized nanoparticles, which helps us to study crystalline nature, functional groups, and morphological studies, and to identify its stability. 

A. A. Herzing et al. Energy dispersive X-ray spectroscopy of bimetallic nanoparticles in an aberration corrected scanning transmission electron microscope, Faraday Discuss., 2008, 138(0), 337-351. 

Probing plasmonic resonances using low-loss electron energy loss spectroscopy has proved particularly useful for studying the optical properties of noble metal nanoparticles. Single particle plasmonic studies are an important tool to understand the role of size, shape and local environment on the exact nature of plasmonic excitations that might be complicated by dispersity of these traits when using bulk techniques. 

Fig. 2 TEM images of two carbon-supported PtNi catalysts with different Pt Ni ratios (Itfi) and particle-size distributions for the metal nanoparticles right). Inset shows energy-dispersive X-ray spectroscopy (EDS) spectrum for the Pt2Nii/C catalyst. (From [27] with permission from Elsevier)...

---