TiO₂ Nanoparticles‐Photocatalytic Oxidation of Selected Cycloalkanols

Abstract

Photocatalytic oxidation of cyclohexanol ( 1 ), cyclopentanol ( 2 ), and cycloheptanol ( 3 ) was investigated by using titanium dioxide (Degussa P25) as a semiconductor photocatalyst .The effect of different operational parameters such as the catalyst, the solvent, time, and oxidant was also studied. Results showed a high percentage of conversion for 1 – 3 (71.6%, 94.2%, and 100%, resp.) and that the primary photocatalytic oxidation products are the corresponding cycloalkanones ( 4–6 ). They were formed with high selectivity (>85%). Several other products were also identified using GC, GC/MS techniques and authentic samples. The photocatalytic activity is explained by a photoinduced electron transfer mechanism through the formation of electron‐hole pair at the surface of the semiconductor particles. A first‐order kinetic model was observed for the photocatalytic oxidation of the investigated cycloalkanols.