Controlled Synthesis of Anatase TiO₂ Single Crystals with Dominant {001} Facets from TiO₂ Powders

Abstract

Anatase TiO2 single crystals with dominant {001} facets were fabricated in a controlled manner from TiO2 powders through a facile route for the first time. The obtained TiO2 single crystals have a size of approximately 1.5 μm and a remarkable, roughly 65 % fraction of {001} facets. The influence of the reaction temperature, the amount of precursor, and the reaction time on the morphology and the exposed facets was studied systematically. The percentage of {001} facets increased with the temperature and the amount of precursor, as a result of the surface energy reduction effect of F− ions. Further increasing the temperature and the amount of precursor led to serious corrosion of the products because of the enhanced corrosive effect of HF. Owing to the high percentage of exposed {001} facets, the TiO2 single crystals exhibit a much enhanced photocatalytic efficiency (almost fivefold) compared to that of P25 TiO2 as a benchmark material, thus opening a new avenue to prepare highly active TiO2 single crystals with dominant {001} facets from low‐cost TiO2 powders.

“Crystallographic” holes: new insights for a beneficial structural feature for photocatalytic applications

“…As already stated, much effort has been focused on developing new routes for preparing {001} facets dominated anatase TiO 2 single crystals. 3,[7][8][9][10][11][12][13][14][15][16][17] There are different synthesis paths to produce TiO 2 crystals, such as trough titanate nanotubes (TNTs) in supercritical water. The transformation of the TNTs into anatase nanocrystals was achieved by two simultaneous processes (dissolution-nucleation and crystal growth while the other is an in situ nucleation and crystal growth).…”

Enhanced Photocatalysis from Truncated Octahedral Bipyramids of Anatase TiO2 with Exposed {001}/{101} Facets

“…This shaped the crystals into the observed TOBs. 48 However, due to the strong bonding interaction, the F (aq) – ions capped on the TOB surfaces were difficult to remove. The blockage reduced the number of active surface sites, and consequently, the photocatalytic performances of these samples were degraded.…”

Facile Preparation of Efficient WO3 Photocatalysts Based on Surface Modification

“…This additional light absorption can be attributed to the d-d transition of Cu(II) [18]. After further modification with TiO 2 powders, the interband transition of WO 3 was not changed, due to the small amount of TiO 2 powders and their large band gap [13][14][15]. Notably, the additional visible light absorption caused by the d-d transition of Cu(II) can still be observed in the mixed nanocomposites, proving the existence of Cu(II) nanoclusters (inset of Figure 3).…”

“…Titanium dioxide (TiO 2 ) has attracted much attention as a suitable semiconductor to construct heterogeneous structures with WO 3 , due to its low cost, nontoxicity, and suitable band structure [5,[13][14][15][16]. The valence band (VB) and CB potentials of TiO 2 are more cathodic than those of WO 3 [16].…”