Li*diffusion in TiO2 Anatase unit cell Modelling data: Li ions diffuse along the zigzag pathway and reside at the octahedral voids. The diffusion pathway is approximately along the c-direction. Energy barrier is lowest across (001)plane Hypothesis: Building nanostructured TiO2 with exposed(001)plane(perpendicular a to c-axis)will probably facilitate Lit diffusion in anatase. O Ti L计 Li'diffusion path 6
6 Anatase unit cell Modelling data: • Li ions diffuse along the zigzag pathway and reside at the octahedral voids. • The diffusion pathway is approximately along the c-direction. • Energy barrier is lowest across (001) plane Hypothesis: Building nanostructured TiO2 with exposed (001) plane (perpendicular to c-axis) will probably facilitate Li+ diffusion in anatase. Li+ diffusion in TiO2
(001)Facet of Anatase TiO2 LETTERS Anatase TiOz single crystals with a large percentage of reactive facets Hua Gui Yang'*,Cheng Hua Sun.2*,Shi Zhang Qiao',Jin Zou3,Gang Liu.4,Sean Campbell Smith2, Hui Ming Cheng&Gao Qing Lu much more reactive (001}facets-13,18-20.Here we demonstrate that for fluorine-terminated surfaces this relative stability is reversed: (001}is energetically preferable to {101).We explored this effect systematically for a range of non-metallic adsorbate atoms by first-principle quantum chemical calculations.On the basis of theoretical predictions,we have synthesized uniform anatase TiO2 single crystals with a high percentage(47 per cent)of (001} facets using hydrofluoric acid as a morphology controlling agent. Moreover,the fluorated surface of anatase single crystals can easily be cleaned using heat treatment to render a fluorine-free surface Hua Gui YANG without altering the crystal structure and morphology
(001) Facet of Anatase TiO2 Hua Gui YANG
(001)Facet of Anatase TiO, /98 (001) (101) a b 2c-0 6c-Ti 5c-Ti 2c-0 5c-Ti 3c-0 Highest surface energy of 0.9 J m2 (vs.0.44 J m-2 of (101) surfaces) Unsaturated Ti and O atoms,and unequivalent Ti-O bonds Problem:Quick diminishment during synthesis Yang et al.,Nature,2008,453,638
• Highest surface energy of 0.9 J m-2 (vs. 0.44 J m-2 of (101) surfaces) • Unsaturated Ti and O atoms, and unequivalent Ti-O bonds • Problem: Quick diminishment during synthesis (001) (101) (001) Facet of Anatase TiO2 Yang et al., Nature, 2008, 453, 638
Analyze surface stabilizing agents 1/936 (001) (101)
Analyze surface stabilizing agents (001) (101)