Synthesis Of TiO2 Hollow Spheres Research Articles

Hydrothermal synthesis of TiO2 hollow spheres adorned with SnO2 quantum dots and their efficiency in the production of methanol via photocatalysis.

TiO2 hollow spheres and TiO2 hollow spheres adorned with SnO2 quantum dots were synthesized successfully under mild temperature and autogenous pressure using the hydrothermal route. X-ray diffraction, field emission scanning electron microscopy, scanning electron microscopy, transmission electron microscope, photoluminescence spectroscopy, and UV-vis spectroscopy were used to characterize the physical and chemical nature of the synthesized sample. The characterized samples were used in the photocatalytic applications to reduce the concentration of carbon dioxide in the presence of water under the influence of visible light. Our observation confirmed that with increasing SnO2 content there is a tremendous change in the photocatalytic performance of the samples, due to free mobility of the electrons and holes and decline in charge recombination centers formed with the formation of nano-heterojunction between SnO2 and TiO2. The greater photocatalytic production of methanol was achieved using 2ST sample, i.e., 1.61μmol/g/h which tends to decrease with an increase in SnO2 content.

Design and Synthesis of TiO₂ Hollow Spheres with Spatially Separated Dual Cocatalysts for Efficient Photocatalytic Hydrogen Production.

TiO2 hollow spheres modified with spatially separated Ag species and RuO2 cocatalysts have been prepared via an alkoxide hydrolysis–precipitation method and a facile impregnation method. High-resolution transmission electron microscopy studies indicate that Ag species and RuO2 co-located on the inner and outer surface of TiO2 hollow spheres, respectively. The resultant catalysts show significantly enhanced activity in photocatalytic hydrogen production under simulated sunlight attributed to spatially separated Ag species and RuO2 cocatalysts on TiO2 hollow spheres, which results in the efficient separation and transportation of photogenerated charge carriers.

Synthesis of TiO2 hollow spheres with tunable pore structure and enhanced photocatalytic activity

Titania hollow spheres were fabricated successfully by using tetrabutyl titanate as titanium precursor and colloidal carbon spheres as hard templates. The microstructure, textural properties, structure regulation approach, as well as the photocatalytic properties of the hollow spheres were investigated. The results show that the hollow spheres possess the perfect spherical shape, monodispersity, and hierarchically pore structures which endow them with high specific surface area and pore volume. The wall thickness and textural properties of the hollow spheres can be easily tailored by adjusting the concentration of tetrabutyl titanate. Evaluation of the titania hollow spheres for the photo-decomposition of methylene blue (MB) under visible-light irradiation reveals that they exhibit excellent photocatalytic activity and durability.

N-doped Ag/TiO2hollow spheres for highly efficient photocatalysis under visible-light irradiation

This paper describes the synthesis of TiO2 hollow spheres (HSs) modified via nitrogen doping and silver loading (Ag–N–TiO2) with particle diameters of ~100 nm. The specific surface area of the Ag–N–TiO2 was up to 147 m2 g−1 and this structure is stable upon high temperature treatment. Ag–N–TiO2 exhibited excellent photocatalytic activity for the degradation of dye compounds under visible light irradiation (≥410 nm) due to their larger surface area and controlled morphology compared with previously reported N-doped TiO2 fine particles (e.g. N–P25).

Synthesis of TiO2 hollow spheres using binary ionic liquids as an electrocatalyst

Titanium dioxide (TiO2 titania) hollow sphere was simply synthesized using various ionic liquids (ILs). The shape and size of TiO2 particles were significantly different with the composition of ILs. This is mainly attributed to the interaction between organic solvent and IL at the interface leading to the formation of sphere. Among the binary ILs, [Bmim][BF4] + [Omim][PF6], [Bmim][BF4] + [Omim][PF6], and [Bmim][PF6] + [Hmim][PF6] were useful to prepare TiO2 nanostructures with high surface area and anatase phase. Especially, [Bmim][BF4] + [Omim][PF6] was the most effective IL to synthesize an anatase TiO2 hollow sphere.

Facile Synthesis of Mesoporous TiO2 Spheres with Hollow Interiors

The Mesoporous TiO2 hollow spheres are synthesized by a solvothermal reaction without any surfactant and template. The reaction conditions such as reaction temperature, type of precursor, solvent used and their influence on the synthesis of TiO2 hollow spheres are investigated. The synthesized TiO2 hollow spheres are characterized by X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), focused ion beam (FIB) SEM, Barrett-Emmett-Teller (BET) surface areas, and UV-visible diffused reflectance spectroscopy. The synthesized TiO2 spheres have obtained different diameters ranging from 700 nm to 1.79 μm at different reaction temperatures. The shell is composed of numerous single crystalline nanoparticles. The morphology and interiors of the spheres strongly depend upon the experimental parameters such as reaction temperature and a kind of solvent. Especially, interiors of TiO2 hollow spheres such as mesoporous, double shell and single wall structures at various reaction temperatures are discussed with the aid of TEM and FIB SEM measurements.

Two-step template-free route for synthesis of TiO2 hollow spheres

The TiO2 hollow microspheres were prepared by microwave-assisted solvothermal treatment without template. The morphology and the phase of TiO2 hollow microspheres were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and BET surface areas. The results show that the particles have hollow structures and the shell was covered by nanocrystals and have higher specific surface area. The possible formation mechanism of hollow TiO2 spherical structures has simply been proposed. The activity was evaluated by the photocatalytic degradation of methyl orange (MO). The results show that the particles having specific surface area show higher photocatalytic activity. It can be attribute to the doped F atoms and the creation of oxygen vacancies.