Abstract. 12 hybrid photocatalysts consisting of titania (TiO2) and an adsorbent such asmordenitewere investigated for the photocatalytic decomposition of toluene, a major indoor contaminant in indoor air. The highest decomposition ratewas obtained with the use of mordenite and silicon dioxide (SiO2) as additives to TiO2. The photocatalytic activities of hybrid photocatalysts in decomposing…