Fig. 3. Basic techniques for the characterization of nano-materials. Chemical characterization includes optical spectroscopy such as optical absorption spectroscopy, which includes UV-Vis spectroscopy, photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy; and electron spectroscopy including energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), auger electron spectroscopy (AES), and ultraviolet photoelectron spectroscopy (UPS). Structural characterization involves X-ray diffraction (XRD); electron microscopic techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), environmental transmission electron microscopy (ETEM), and scanning probe microscopy (SPM); and dynamic light scattering (DLS) using a particle size analyzer.