Development of nano-structural and porous photocatalytic TiO2 air filters system for removal of air pollutants

(RGC Earmarked Grant, PolyU 5204/07E, HK$ 394,800, 2008-2010): Photocatalysis offers a new alternative for gaseous pollutant removal. The aim of this project is to develop an advanced air filtration systems that improve indoor/outdoor air quality. The proposed approach couples the nano-scale architecture with TiO2 photocatalysis, which provides a promising method for air pollutant removal. Porous and nano-structural TiO2 photocatalyst with enhanced photocatalytic activity prepared by different novel preparation methods can be immobilized on different type of air filters by our new developed hydrothermal induced gas-phase crystallization method. Our new approach not only induces gasphase crystallization of TiO2 under hydrothermal treatment, the new formed TiO2 are also inherently bound to the nanostructural TiO2 powder during the formation, leading to a good adhesion of the TiO2 film to the substrate. The most attractive feature of this method is that we need not restrict the preparation of TiO2. TiO2 powders can be prepared by different methods, and then bound to the substrates without damage the nanostructure. This method also overcomes the traditional problems of TiO2 photocatalyst, i.e. low surface area, poor adhesion, poor thermal stability of substrates, and combines the feature of nano-architectural materials which greatly enhances the photocatalytic efficiency for degrading air pollutants to form more environmentally acceptable products.

Funding Source: RGC - General Research Fund (GRF)