First principle study to correlate location and activity of ruthenium oxide incorporated in alkali-metal hexatitanates

Ab initio total energy pseudopotential calculations were performed on ruthe nium oxide incorporated alkalimetal hexatitanates to study the location and activity of ruthenium oxide. The influence of alkali metals on the activit y is also monitored. The photocatalytic activity of alkali-metal hexatitana tes in the presence of ruthenium oxide increases in the order Na > K > Rb. To rationalize the role of the hexatitanate structure on its activity, both ruthenium oxides incorporated and unincorporated structures were investiga ted. One objective is to monitor whether the ruthenium oxide incorporated i n the tunnel has photocatalytic activity or not. The present results sugges t that the tunnel structure in the Na-hexatitanate framework is well suited for accommodating Ru species and induces strong interaction between the ac tive species and the host oxide. Density of state calculations were perform ed on both structures (with and without ruthenium oxide) to verify the acti vity of ruthenium oxide. It is observed that ruthenium oxide residing in th e inner tunnels of the hexatitatanate structure plays an active role in pho tocatalysis. A novel methodology has been formulated to explore other compl icated inorganic materials of interest.