Unique Anatase TiO₂ Twinning Crystals Formed by High-Energy {001} Facets and the Improved Photocatalytic Activity

Abstract

For the first time, anatase TiO2 twin crystals have been synthesized by a simple hydrothermal method. The samples are characterized using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, ultraviolet–visible diffused reflectance spectra, and nitrogen sorption isotherms. It is found that a prolonged reaction time significantly contributes to the structure evolution and that twin crystals form via the oriented attachment (OA)- and Ostwald ripening (OR)-controlled secondary growth mechanism. Remarkably, the photoactivity of TiO2 twin crystals is 2.57 and 8.74 times higher than that of single-crystalline anatase TiO2 nanosheets and rutile TiO2, respectively. This has been mainly ascribed to the unique twin crystal structure. This work is a big step toward further improvement of the photocatalytic properties of of TiO2.

Photocatalytic and Photoluminescence Properties of Core–Shell SiO2@TiO2:Eu3+,Sm3+ and Its Etching Products

“…As a promising material for photoluminescence, catalysts, solar cells, anatase TiO 2 has been studied intensively, because of its excellent electrical, optical, and photochemical properties. − As such, photodegradation and luminescence properties of the pure TiO 2 matrix have been investigated for a long time. However, single-component matrix still has some problems: nanoparticles agglomerated easily, and the capping ligands that were used to maintain colloidal stability would occupy the active sites of TiO 2 , which limited its practical application .…”

Microflowery, Microspherical, and Fan-Shaped TiO2 Crystals via Hierarchical Self-Assembly of Nanorods with Exposed Specific Crystal Facets and Enhanced Photocatalytic Performance

“…It is universally acknowledged that the separation efficiency of photogenerated electron-hole pairs has an essential impact on the photocatalytic activity. The high conductivity of the AS-TiO 2 sample also facilitates electron transfer, resulting in an efficient charge separation [41]. The low conductivity of the AC-TiO 2 , urea-TiO 2 , and No-TiO 2 samples with the same trend was not conducive to electron transfer, resulting in an inefficient electron-hole separation.…”

Synthesis of Bi–Fe–Sb–O Pyrochlore Nanoparticles with Visible‐Light Photocatalytic Activity

“…Analogous improvements have been reported recently for other oxide photocatalysts prepared by soft chemistry methods through the oriented attachment of nanoparticles. [23][24][25][26][27] Eur. J. Inorg.…”