Photocatalytic antimicrobial and antiviral coatings

Surface contamination in public places plays an important role in the transmission of healthcare-associated pathogens. Traditional cleaning and disinfection methods are proven largely ineffective for complete decontamination of surfaces by microbes and viruses, such as multidrug-resistant ‘superbugs’ and coronavirus. Recent studies have shown that light-based approaches e.g. photocatalysis, can kill multidrug resistant bacteria and viruses and do not induce themselves any resistance.

Anatase titanium oxide (TiO2) is well known to possess photocatalytic effect under UV illumination. This effect has been used in applications such as medical device disinfection and sterilisation. The reactive-oxygen species generated under UV illumination can decompose organic compounds and damage bacterial cell membranes thus are useful for killing bacteria. More interestingly, some antibiotic-resistant pathogens e.g. methicillin-resistant S. aureus, and multidrug-resistant A. baumannii seem more susceptible to TiO2 photocatalysis. However, the wide bandgap of TiO2 makes it difficult to use under visible light. It is necessary to modify TiO2 with dopants to make it photocatalytic under visible light. Tungsten trioxide (WO3), on the other hand, has a narrow bandgap and is considered to be a visible-light-driven photocatalyst. However, pure WO3 is not a particularly high-efficient photocatalyst because of the high electron-hole recombination rate and the difficulty in the reduction of oxygen, due to the negative position of its conduction band. Modifications are also needed to enhance its photocatalytic performance under visible light.

The aim of this PhD project is to investigate visible-light-activated photocatalytic antimicrobial coatings based on heterogeneous TiO2 and WO3 that can be used on touch surfaces in healthcare settings such as hospitals, intensive care units and care homes. The project involves the formulation of material composition, microstructural and microbiological characterisation using a range of analytic and microscopic techniques such as XRD, SEM, TEM, FTIR, UV-Vis and biofilm assays.

Applicants with a BSc or MSc (or equivalent) in Materials, Chemistry, Engineering, Microbiology or other relevant discipline are encouraged to apply. For further information, please contact Professor Bo Su, [Email Address Removed]

When applying please select "PhD in Oral and Dental Science" within the Faculty of Health Sciences.

http://www.bristol.ac.uk/study/postgraduate/apply/