Preparation of porous TiO{sub 2}/silica composites without any surfactants
- College of Chemistry, Jilin University, Changchun 130023 (China)
TiO{sub 2}-SiO{sub 2} composites, with high specific surface area (up to 308 m{sup 2}/g), large pore volume, and narrow distribution with average pore sizes of 3.2 nm, have been synthesized from wollastonite and titanium sulfate in the absence of any surfactants. Calcium sulfate, a microsolubility salt, plays an important role in the formation of pores in this porous TiO{sub 2}/silica composite. The microstructure and chemical composition of composite were characterized by X-ray diffractometry (XRD), transmission electron microscopy (TEM) equipped with energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectrometer (XPS) and N{sub 2} adsorption and desorption analysis. The as-prepared porous titanium dioxide-silicon dioxide composites with high specific surface area and well-crystallized anatase contents were used as an efficient photocatalyst. - Graphical abstract: TiO{sub 2}-SiO{sub 2} composites have been synthesized from wollastonite and titanium sulfate in the absence of any surfactants. In acid Ti(SO{sub 4}){sub 2} solution, Ca and Si ions in chain-like wollastonite could dissolve into the bulk solution and slightly soluble CaSO{sub 4} crystal phase and silicic acid formed. The concentration of the titanium species in the reaction solution is expected to increase with the hydrolysis process, nucleation starts. After the start of the nucleation, a very small amount of TiO{sub 2}, silicate and CaSO{sub 4} particle deposited together and formed composites. Some cavities formed during the washing step through the dissolution of CaSO{sub 4} crystal phase. The bulk of the material is then transformed from wollastonite into TiO{sub 2}/silica composites.
- OSTI ID:
- 21212194
- Journal Information:
- Journal of Solid State Chemistry, Vol. 182, Issue 2; Other Information: DOI: 10.1016/j.jssc.2008.10.027; PII: S0022-4596(08)00541-0; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
Carbonation Behavior of Pure Cement Hydrates under Supercritical Carbon Dioxide Conditions - 12199
Integrated Experimental and Modeling Studies of Mineral Carbonation as a Mechanism for Permanent Carbon Sequestration in Mafic/Ultramafic Rocks
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ADSORPTION
CALCIUM SULFATES
CHEMICAL COMPOSITION
CRYSTALS
DESORPTION
DISSOLUTION
HYDROLYSIS
MICROSTRUCTURE
POROUS MATERIALS
SILICA
SILICATES
SILICIC ACID
SILICON IONS
SILICON OXIDES
SPECIFIC SURFACE AREA
SURFACTANTS
SYNTHESIS
TITANIUM OXIDES
TITANIUM SULFATES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTROSCOPY