Sol-Gel Synthesis and Characterization of Nanoparticles

S Ramesh

doi:10.1155/2013/929321

Abstract

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.

Highlights

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]
The profile was fitted with a pseudoVoigt function, and a polynomial background subtraction was chosen for the refinement
Ti3+ (d1) ions excited states are closer to the ground state in octahedral and tetrahedral symmetry in this case Electron paramagnetic resonance (EPR) lineshapes can only be detected at liquid-helium temperatures due to a very short spin-lattice relaxation time [24, 32]

Summary

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]. 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 [10,11,12]. 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. The structural and chemical properties of the materials have been progressively investigated by several advanced techniques. The aim is to determine the structure and property of the samples by X-ray diffraction, scanning electron microscopy (SEM), differential scanning colorimetry (DSC), optical absorbance spectroscopy, EPR spectroscopy, and vibrating sample magnetometer (VSM)

Experimental

Results and Discussion

Ag μm 17077

B2 B3 B4 B5

Conclusion