tailieunhanh - Preparation of TiO2 nanocrystals in anatase and rutile phase

The concentration of the HCl reaction medium and the following aging are the essential factors affecting the formation and phase composition of the resulting TiO2 nanocrystals. TiO2 nanoparticles in the form of pure anatase and the rutile phase can be extracted and segregated from the suspension and precipitate of the synthesizing medium. | JOURNAL OF SCIENCE OF HNUE DOI Chemical and Biological Sci. 2015 Vol. 60 No. 9 pp. 14-20 This paper is available online at http PREPARATION OF TiO2 NANOCRYSTALS IN ANATASE AND RUTILE PHASE Nguyen Trong Tung1 2 and Duong Ngoc Huyen1 1 School of Engineering Physics Hanoi University of Science and Technology Hanoi 2 College of Television Thuong Tin Hanoi Abstract. TiO2 nanocrystals were prepared by pyrolysis of titanium tetrachloride TiCl 4 as precursor in an HCl aqueous solution at 80 ºC. The morphology and crystal structure of the resulting materials were characterized using a transmission electron microscope TEM X-Ray diffraction XRD and Raman spectroscopy. The concentration of the HCl reaction medium and the following aging are the essential factors affecting the formation and phase composition of the resulting TiO2 nanocrystals. TiO2 nanoparticles in the form of pure anatase and the rutile phase can be extracted and segregated from the suspension and precipitate of the synthesizing medium. Keywords Nanocrystal TiO2 anatase rutile. 1. Introduction TiO2 titanium dioxide is a safe material nontoxic to humans and widely used. TiO2 is considered to be a semiconductor with photocatalytic activities chemical stability long durability nontoxicity and low cost which has great potential for application in pigments catalyst support fillers coatings photoconductors photocatalysts and environment purification 1-4 . For example TiO2 nanoparticles absorb ultraviolet UV light and can therefore be used to filter out sunlight in cosmetics to protect the skin 5 . Photocatalytic properties of TiO2 can also be apply for antibacterial purposes self-cleaning glass and water purification 3 . In the clean energy field TiO2 is used to convert solar energy in dye- sensitized solar cells DSSC and producing energy from hydrogen fuel 5 6 . TiO2 exists in three main structural configurations under normal conditions rutile anatase and brookite in