Mechanics, Materials Science & Engineering, April 2017 – ISSN 2412-5954
Structural, Optical, Morphological and Elemental Analysis on Sol-gel Synthesis of Ni Doped TiO2 Nanocrystallites4 T. Sakthivel1, K. Jagannathan1,a 1 – Department of Physics, SRM University, Vadapalani campus, Chennai-600026, Tamilnadu, India a – kjagan81@gmail.com DOI 10.2412/mmse.80.76.610 provided by Seo4U.link
Keywords: TiO2 nanoparticle, sol-gel synthesis, band gap tuning, photoanode.
ABSTRACT. Pure and Ni doped titanium dioxide nanoparticles were successfully synthesized by sol-gel method and characterized usingXRD, UV-Visible, FTIR, FESEM and EDS techniques. XRD pattern confirms the formation of tetragonal TiO2. The absorbance spectra of pure and Ni doped TiO2 showed absorption spectrum at ultra-violet region due to electronic transition between bonding and anti-bonding orbital (π-π•). Bandgap energy of Ni doped TiO2 decreased to 2.5 eV when compared to pure TiO2 (3.39 eV). FESEM study reveals agglomerated spherical shaped morphology. The functional groups of the prepared samples were identified using FTIR spectroscopy and the elemental analysis was further supported with EDS analysis.
Introduction. TiO2 is the promising material as semiconductor having high photochemical stability, non-toxicity, high surface area and low cost. TiO2 is used in many applications such as pigments, adsorbents, photo catalytic, sensors, Photovoltaic devices. [1-2]TiO2 exhibit three main phases namely anatase, rutile and brookite [3]. Among them anatase phase is formed at a lower temperature with a band gap of 3.0-3.2 eV, whereas for the rutile it is 3.0 eV[4]. Also, it has proven itself as one of the promising material to replace the toxic and expensive other metal oxides like CdO, SnO2, In2O3 and etc., for opto-electronic applications. Among others, TiO2 is a superior one in opto-electronic applications, especially in conducting electrodes of dye-sensitized solar cells (DSSC). But the limitation towards using metal oxides is absorption spectrum in UV region [5]. Different dopants are used in TiO2 for the absorption of visible light, such as transition metal ion doping (Fe, Co, Ni, Cu, Zn and Zr) has been found to be efficient dopants for improved photostability and bandgap tuning[6]. Experimental Procedure Preparation of TiO2 Nanoparticles.The TiO2 nanoparticles were obtained from 5 ml of titanium (IV) isopropoxide (TTIP) dissolved in 5 ml of ethanol with 20 ml of distilled water added to the above solution. The mixed solution was vigorously stirred for 1 hr in order to form a gel. The gel was dried at 75 °C for 5 hr to remove the water and organic materials. Then, the dried gel was sintered at 450°C for 2 hr in high temperature muffle furnace. Finally the pureTiO2 nanoparticles were obtained by solgel method. Preparation of nickel doped TiO2 nano particles.The nickel doped TiO2 nano particles were obtained from titanium (IV) isopropoxide (TTIP) and iso-propanol as the starting material. 5 ml of TTIP was added drop wise to 45 ml of iso-propanol for the TiO2 formation. The solution was vigorously stirred for 45 min to form sols. 5% nickel nitrate was mixed drop by drop to the above
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