Anatase nanoparticles

Residual organics and template materials, surfactants and polymers, can be removed simply by heating at temperatures up to 500°C. The heated gels at temperatures up to 600°C consist of anatase nanoparticles. Anatase titania is known to have higher photocatalytic activity than other crystalline phases of titania. At temperatures higher than 600°C, the phase... 

Figure C2.17.8. Powder x-ray diffraction (PXRD) from amoriDhous and nanocry stalline Ti02 nanocrystals. Powder x-ray diffraction is an important test for nanocrystal quality. In the top panel, nanoparticles of titania provide no crystalline reflections. These samples, while showing some evidence of crystallinity in TEM, have a major amoriDhous component. A similar reaction, perfonned with a crystallizing agent at high temperature, provides well defined reflections which allow the anatase phase to be clearly identified.

In this study, nanoparticles of titanium dioxide (TiCh) have been successfully synthesized by. reduction method. These nanoparticles were characterized by using X-ray diffraction (XRD) and TEM (transmission electron microscopy). XRD revealed the presence of pure TiCL NPs. XRD studies suggested that the titanium dioxide, TiCL exists in anatase form. The nanostructured character of the produced titania powders was characterised by Scherer method and TEM examinations. The TEM images indicate that the crystalline size of titanium dioxide precipitates varies from 1.81 nm to 13.15 nm This shows that nanoparticles obtained from reduction method are in more nanorange as compared to those obtained for precipitation method. 

Nanosized anatase (< 10 nm) and brookite ( 70 run) particles have been successfully synthesized via sonication and hydrothermal methods. Figure 5.1 shows the powder XRD patterns of as-synthesized anatase and brookite nanoparticles. The particle sizes were characterized by XRD and scanning electron microscopy (SEM) (Fig. 5.2). 

Abstract A colloidal solution of titanium dioxide (TiO ) nanoparticles was prepared by the solvothermal method and dip-coated onto a polypropylene fabric with TMOS binder. The prepared TiO particles, colloidal solution and the coated fabrics were characterized by X-ray diffraction, SEM and TEM. The results showed that the TiO particles prepared by the solvothermal method were composed of anatase which uniformly coated the snbstrate. Photocatalysis induced bactericidal properties of coated fabrics were tested by measuring the viability of Escherichia coli. It was fonnd that solvothermally prepared TiO coatings have the ability to kill E. coli. This nniqne property of TiO makes it an ideal candidate in producing self-sterilizing protective masks and in providing bactericidal and self-cleaning properties to a variety of snrfaces. 

Fig. 17 Spindle-like hematite (10) [534] and anatase (11) [533] nanoparticles coated with calamitic liquid crystals...

Lana-Villarreal T, Rodes A, Perez JM, Gomez R. A Spectroscopic and electrochemical approach to the study of the interactions and photoinduced electron transfer between catechol and anatase nanoparticles in aqueous solution. J Am Chem Soc 2005 127 ... 

---