Research > Research Projects
Dr. HO Wing Kei - Novel metal-free heterojunction visible-light-driven photocatalyst for air purification and bacterial inactivation
Chief Investigator:

Dr. HO Wing Kei

Project Year:



(Dean’s Research Fund, HKIEd, HK$300,000 2014-2015), The purpose of this study is to synthesize the novel metal-free heterojunction visible-light-driven photocatalyst in order to enhance their photocatalytic ability for air purification and bacterial inactivation. Photocatalytic degradation of pollutants to nontoxic carbon dooxied and water under visible light irradiation (43% of the incoming solar energy) has been regarded as one of the best green strategies to solve the pollution problem. Recently, non-oxide-type photocatalysts, particularly graphitic carbon nitrides (g-C3N4) are proven to be active under visible light irradiation. This finding opens up important new possibilities for solar-driven photocatalysts for environmental purification. Although significant efforts have been devoted to develop stable and efficient g-C3N4, their efficiencies are not high enough for practical applications. The low efficiencies may be attributed to their low surface areas or poor crystallinity. In addition, the catalytic, electronic and optical properties of the g-C3N4 are by principle adjustable, using the rich chemistry of carbon and nitrogen. Several studies have been conducted to bind or intercalate different compounds, metals or non-metals into the matrix, which provides a convenient means of fine-tuning the structure and reactivity of g-C3N4. We propose an 18 months study to develop a new class of metal-free heterojunction photocatalysts prepared by coupling the g-C3N4 (CN) with different metal-free photocatalyst visible-light-driven with suitable band-structure alignments. Possible mechanism will also be investigated for the photocatalytic oxidative inactivation and reductive inactivation. As a proof-of-concept, this work will be offer new inroads into exploration and utilization of nanocomposites of different metal-free heterojunction photocatalysts with g-C3N4 for environmental applications, i.e. air purification and bacteria inactivation.