Sol-Gel Synthesis and Characterization of Nanoparticles

The nanoparticles have been synthesized by sol-gel technique. X-ray diffraction, scanning electron microscopy, optical absorption spectroscopy, and electron paramagnetic resonance spectroscopy were used to characterize the sample. The X-ray diffraction results indicate the formation of nanocrystalline materials in tetragonal lattice with P42/nnm space group. The identical distribution of elements were confirmed by scanning electron microscopy with energy dispersive X-ray spectrometry and X-ray mapping. Electron paramagnetic resonance lineshapes of the samples are obtained at various (13？K, 77？K, and 300？K) temperatures. The isotropic lineshapes of the sample B1 are attributed to dipole-dipole interaction of Ti3+ ions. The incorporation of Al3+ ions into the sample B2–B5 the isotropic nature of the lineshapes are collapsed due to the distraction in crystal field. Optical absorption spectra results reveal the presence of Ag-TiO2 nanoparticles. 1. Introduction Titanium-based nanoparticles have been studied intensively owing to its widespread industrial applications such as cosmetics [1], ceramics [2], superconductivity [3], solar cells [4], magnetic [5], shape memory alloys [6], and photocatalysis [7]. However, the basic research and industrial development of TiO2 containing samples are hot topics because of its extensive potential importance, and existing difficulties are still tough to solve [8, 9]. The key problems of TiO2 containing samples show short wavelength excitation, it may crossover by the addition of noble metals such as Ag, Au, Pt. Among them, silver and gold nanoparticles are promising due to the remarkable chemical stability and a characteristic absorption peak in visible wavelength range [10–12]. The enriched photoactivity in visible light is attributed to the silver nanoparticles act an electron traps aiding electron-hole separation [13]. In favor of some specific advanced application (optics, sensor, photocatalysis, etc.), materials are appropriate to shape as films, tubes, and fibers but in most cases TiO2 samples are required as a powder. Various wet chemical methods such as coprecipitation [14], hydrothermal [15, 16], sol-gel technology, and combustion method [17, 18], have been developed for materials synthesis. Since the sol-gel technology is widely used and it is an effective process to produce Ag-TiO2 nanoparticles is due to its advantages of low processing cost, energy efficiency, high production rate, and rapid productivity of fine homogeneous powder [19–23]. Characterization of materials are the root of modern technology for