Development of Advanced Visible-light-driven photocatalytic Nano-coating Technologies for Indoor/Outdoor Air Pollution Control

(Central Research Grant , PolyU, HK$ 696,000, 2006-2008): The rapid pace of development in the Pearl River Delta region inevitably causes serious air pollution. While government officials from Guangdong and Hong Kong are negotiating for a long-term solution, the poor air quality has become a major threat to public health. Near-term advanced technologies for indoor and outdoor air quality improvement are urgently needed. The TiO2 photocatalytic technology is a promising way to solve the problem because of its potential applications in environmental remediation. It provides a convenient and efficient technique for decontamination, purification and deodorization of air. However, TiO2 can only be activated by UV irradiation. In addition, TiO2 photocatalyst in the form of powders are difficult to recycle and have the drawback of post-separation after photoreaction. It is desirable to develop a TiO2 photocatalytic coating that efficiently absorbs visible light, which occupies the main part of the solar spectrum. The objective of this project is to nurture a new industry in Hong Kong that manufactures high value-added products with visible-light-driven photocatalytic coatings. These include building materials that break down air pollutants and clean themselves, advanced air filtration systems that improve indoor and outdoor air quality, and even bactericidal hospital/household wares. Novel preparation methods such as non-metal doping and creation of oxygen deficiency will be applied. Building materials (glass, tiles, and metals) and air cleaner filters will be used as the support for the coatings. Such advanced materials have immense industrial potentials because they can degrade air pollutants to form more environmentally acceptable products and kill bacteria under visible light. These photocatalytic coatings should be most applicable in indoor and outdoor locations with serious air pollution problems.

Funding Source: UGC - Other Specific Funds/Earmarked Grants^