Indoor air environments typically contain higher concentrations of Volatile Organic Compounds (VOCs) than outdoor environments. The presence of VOCs in indoor environments is responsible for ‘Sick Building Syndrome’ which manifests itself as nausea, headaches, fatigue and other symptoms. Many of these VOCs are known or suspected carcinogens and their low concentrations in this environment make them difficult to remove by conventional means.
In principle, photocatalysis is a method suited to removing VOCs from indoor environments as it operates under ambient conditions and is useful for low (ppm) organic concentrations. However, the most prevalent photocatalytic material, titanium dioxide (TiO₂), can only be activated by ultra-violet light which is typically not present in indoor environments. Other simple metal oxides, such as tungsten trioxide (WO₃), demonstrate visible light photoactivity and present a means of overcoming the UV-light dependence of photocatalysts such as TiO₂. In this study the effect of morphology of WO₃ particles on their visible light photoactivity was investigated. WO₃ particles were fabricated by a hydrothermal method and assessed for the photodegradation of ethylene and acetaldehyde in the gas phase. The effect of loading platinum (Pt) on the WO₃ surface was also considered. WO₃ particles with a cuboid morphology provided the highest visible light photoactivity while adding Pt to the surface improved the performance of all WO₃ structures.