A Modified Thermal Treatment Method for the Up-Scalable Synthesis of Size-Controlled Nanocrystalline Titania

Abstract

Considering the increasing demand for titania nanoparticles with controlled quality for various applications, the present work reports the up-scalable synthesis of size-controlled titanium dioxide nanocrystals with a simple and convenient thermal treatment route. Titanium dioxide nanocrystals with tetragonal structure were synthesized directly from an aqueous solution containing titanium (IV) isopropoxide as the main reactant, polyvinyl pyrrolidone (PVP) as the capping agent, and deionized water as a solvent. With the elimination of the drying process in a thermal treatment method, an attempt was made to decrease the synthesis time. The mixture directly underwent calcination to form titanium dioxide (TiO 2 ) nanocrystalline powder, which was confirmed by FT-IR, energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analysis. The control over the size and optical properties of nanocrystals was achieved via variation in calcination temperatures. The obtained average sizes from XRD spectra and transmission electron microscopy (TEM) images showed exponential variation with increasing calcination temperature. The optical properties showed a decrease in the band gap energy with increasing calcination temperature due to the enlargement of the nanoparticle size. These results prove that direct calcination of reactant solution is a convenient thermal treatment route for the potential large-scale production of size-controlled Titania nanoparticles.

Structural and Optical Properties of Ag Nanoparticles Synthesized by Thermal Treatment Method

“…As the temperature of calcination increased, the thermal vibration and mobility of the particles increased as well, which prevents further agglomeration of the particles. Due to increasing thermal vibration and repulsive action of conduction electrons surrounding Ag nanoparticles, the particle size was limited to less than 8 nm when compare to more than 10 nm for semiconductor nanoparticles such as ZnO [ 43 ], CdO [ 44 ], TiO 2 [ 45 ] and ZrO 2 [ 46 ] synthesized by thermal treatment method. Moreover, the particle size of the quantum dots increased with increasing calcination temperature due to particle agglomeration.…”

“…To overcome some of these shortcomings, the thermal treatment method is proposed here for the synthesis of metal nanoparticles for the first time. This method was intended to synthesize oxide nanomaterials, such as metal ferrite nanoparticles: ZnFe 2 O 4 , MnFe 2 O 4 , and CoFe 2 O 4 [39,40,41]; metal chromic nanoparticles, ZnCr 2 O 4 [42]; and semiconductor nanoparticles such as ZnO [43], CdO [44], TiO 2 and ZrO 2 [45,46]. By removing oxygen via nitrogen flow during calcination in an aqueous solution containing metal precursor and polyvinyl pyrrolidone (PVP), the metal nanoparticles can be manufactured using the thermal treatment method.…”

Optimized Loading of TiO2 Nanoparticles into Electrospun Polyacrylonitrile and Cellulose Acetate Polymer Fibers

“…The Tauc plot gives good approximation of the indirect band gap energy of the nanoparticles. The plot of ðαhvÞ 1/r against hv reveals a linear region just above the optical absorption edge, where r = 2 is used for direct allowed transition, r = 1/2 is used for indirect allowed transition, and hv is the photon energy (eV) [25,29]. Figure 3(b) shows the Tauc plot for band gap calculations.…”

Synthesis and characterization of magnesium doped titania for photocatalytic degradation of methyl red

“…anatase and rutile whereas MDT-4 contains purely anatase phase of titania. As concluded by the previous scientists that photcatalytic activity improves when anatase and rutile phases co-exist owing to the utilization of electron-hole pairs among interconnecting particles of both the phases [38].…”