Nonhydrolytic Route to Boron‐Doped TiO₂ Nanocrystals

Abstract

A simple synthesis was applied and tested for the preparation of boron-doped titanium dioxide [TiO 2 (B)] nanocrystals using titanium tetraisopropoxide (TTIP) together with boric acid (H 3 BO 3 ) and benzyl alcohol as reaction solvent. Changes in the TTIP/H 3 BO 3 molar ratio allowed a scalable synthetic protocol with a significant B-dopant control. In particular, this approach does not need surfactants or a final calcination step. X-ray diffractometry (XRD), low-and high-resolution transmission electron microscopy (TEM and HRTEM), and micro Raman spectroscopy revealed that the TiO 2 nanocrystals produced have diameters up to about 10 nm and are mainly of the anatase phase but that a brookite phase was progressively formed with increased dopant Eur.

Microwave-Assisted Synthesis of Boron-Modified TiO2 Nanocrystals

“…Aspect ratios followed these trends, while rod diameters had almost the same value for all the samples (Table 1). This careful analysis confirms that the increased effective boron amount is a limiting factor in the nanocrystal size, as found in our previous work [18]. Moreover, OA not only tuned the morphology, driving the nanorod formation, but also influenced the effective amount of boron in the nanocrystals.…”

“…The nanorods elongation gradually decreased as the amount of oleic acid increased for the 1:1 TTIP:BA nominal ratio, while it gradually increased as the amount of oleic acid increased for the 1:2 TTIP:BA nominal ratio. It should have been expected that increasing amounts of BA would have simply determined a decrease of the rod size, according to the limiting effect on nanocrystal growth demonstrated in a previous work, but here, the OA additions presented the ability to influence the nanocrystal growth with different trends for the two tested nominal BA ratios [18]. Table 1.…”

“…Non-aqueous synthetic approaches have been explored to prepare TiO 2 nanocrystals with an improved control over particle size, shape, crystallinity and surface properties [15][16][17][18].…”

“…For the abovementioned reasons, it is interesting to explore new convenient synthetic routes to finely tune the properties of boron-modified titanium dioxide, TiO 2 :(B), using simple one-step methods. In our previous work, a simple synthesis was applied to prepare B-modified nanocrystals using titanium tetra-isopropoxide (TTIP) together with boric acid and benzyl alcohol as the reaction solvent [18].…”

Properties of Aluminosilicate Refractories with Synthesized Boron-Modified TiO2 Nanocrystals

“…The XRD patterns revealed only the presence of the anatase phase and were analysed by using a whole-profile Rietveld-based fitting program [16] according to the following procedure, fully described elsewhere [11][12][13][14][15]:…”