TiO2-photocatalyzed oxidation of adamantane in solutions containing oxygen or hydrogen peroxide

Photocatalyzed oxidation of adamantane has been investigated using several kinds of TiO2 powders in a mixed solvent of acetonitrile and butyronitrile under aerated conditions. 1-Adamantanol, 2-adamantanol, and 2-adamantanone are obtained as the main products, in which 1-adamantanol is produced at the highest yield. The quantum efficiencies for the production of 1-adamantanol, 2-adamantanol, and 2-adamantanone reach 6.4, 1.0 and 2.1%, respectively. Generally, anatase powders show higher activity than rutile powders. However, by addition of hydrogen peroxide to the solution, the activity of rutile powders is remarkably enhanced and becomes much higher than that of anatase powders. The rate for the production of 1-adamantanol is increased by more than 10 times, and the quantum efficiency for the production of 1-adamantanol reached as high as 25%.