This work presents a photocatalysis-based method to treat and purify air because of its broad applicability to common, oxidizable, air contaminants. The effect of oxygen content, temperature, water vapor, and 2-propanol concentration on the TiO2 surface was investigated. The rate of 2-propanol decomposition increased with increasing the oxygen content, but was reduced at temperatures higher than 100degreesC. When water vapor concentration was in the range of 10-355 mmol m(-3), the rate of 2-propanol decomposition was proportional to the water content. However, an opposite result was observed at a higher concentration of water vapor. 2-Propanol was photooxidized to acetone, and eventually to carbon dioxide and water. The kinetic model of 2-propanol photooxidation was successfully developed by the competitive Langmuir-Hinshelwood rate form, incorporating the inhibition effect coming from the formation of acetone. (C) 2004 Society of Chemical Industry.