Novel hybrid nanostructures for advanced photocatalysis

Photocatalysis makes use of semiconductors to absorb photons to produce photoinduced electrons and holes, which could lead to the reduction and/or oxidation of chemicals. It has been discovered that photocatalysis could be useful for a variety of applications: waste water treatment, air purification, water splitting, CO2 reduction, disinfection and self-cleaning surfaces. In spite that much progress in research has been made, large scale applications in environmental and energy aspect are still on the way due to the common limitations of photocatalysis such as low photocatalytic efficiency and no visible-light-responsive. Various strategies, such as implantation of metal ions, doping of non-metals, modification with other semiconductor components, have been explored in order to improve the photocatalytic activity of TiO2 under visible light. Furthermore, the development of nanoscale functional photocatalysts with appropriate morphologies, such as nanorods, nanowires, nanotubes, and hollow sphere, were also made aiming to enhance the specific surface area and decrease the migration distance of electrons and holes.

Plasmonic photocatalysis has recently been regarded as a very promising technology for high-performance photocatalysis. It involves noble metal nanoparticles (mostly Au and Ag) into semiconductor photocatalysts and obtains drastic enhancement of photoreactivity under the irradiation of UV and a broad range of visible light. In ccomparison with the common semiconductor, plasmonic photocatalyst possesses two remarkable features, i.e. a Schottky junction and localized surface plasmon resonance (LSPR). The Schottky junction results from the contact of the noble metal and the semiconductor, allowing the electrons and holes to pass in different directions once they are created inside or near the Schottky junction. LSPR represents the strong oscillation of the metal’s free electrons in phase with the varying electric field of the incident light, rendering a visible light response to the large-bandgap photocatalysts (e.g., TiO2).

In this project, a new strategy will be developed to design and synthesize novel Au-TiO2 nanostructures as photocatalysts for water splitting, selective oxidation and CO2 reduction applications. A seed-mediated synthesis method will be employed for the preparation of these novel photocatalysts. To combine the large surface area of Au and super thin TiO2 shell, novel morphology for light harvesting and the SPR effect, the Au-modified photocatalysts are expected to exhibit high efficiency for the relevantly photocatalytic reactions.

If you wish to apply for this project, please choose ’PhD Chemical Engineering and Analytical Science’ from the list of available programmes.