High Pressure Studies of nano W-TiO2

• 1、School of chemistry,Beihang University,100083
• 2、Center for High Pressure Science and Technology Advanced Research,Shanghai 201203

Abstract：In this work, the phase transition behavior of W-doped titania nanoparticles was investigated using high pressure X-ray diffraction and high pressure Raman spectroscopy (with pressures up to ~ 32 GPa). Experimental results show that the pressured-induced phase transition of W-doped nano titania to the baddeleyite phase started at ~ 20 GPa. Via comparison with literature reports, we found that pressure medium has obvious influence on the high pressure phase behavior of nano titania - the hydrostaticity of the Ar medium is better than that of sodium chloride or the methanol-ethanol mixture, and hence Ar medium facilitates small titania nanoparticles to retain the baddeleyite crystalline structure at high pressure rather than amorphization. On the other hand, W-doping can induce Ti vacancies in nano titania, making the crystals prone to be atomically distorted under compression, leading to seemingly amorphization seen from the Raman spectra at high pressure.

Keywords： highpressure physics phase transition anatase SynchrotronRadiation