Dr Cameron Shearer

I aim to use fundamental chemistry and materials science to find solutions to environmentally relevant problems such as the destruction of pollutants or the generation of renewable fuels.

Sunlight is the most abundant energy source on Earth yet it is still underutilized in chemical synthesis. Photocatalysis is the key to unlock the potential of light in a range of applications. 

Photocatalytic degradation of persistent organic pollutants (POPs)

Persistent organic pollutants (POPs) can cause cancer and birth defects in humans and are destructive to animal and aquatic lifeforms.^[1] POPs are by-products of some agricultural and industrial processes and do not degrade naturally due to their strong chemical bonds (e.g. C-Cl, C-F) which are resistant to chemical- and bio-degradation (example POPs are shown in Figure 1).

There is a need to develop methods and processes for effective degradation of POPs to mitigate their emerging health and environmental effects.

I synthesise of new photocatalytic materials with designed electronic band structure to break C-Cl or C-F bonds (which are present in all POPs). Materials of interest are titanium and tantalum based perovskites such as SrTiO₃ and NaTa₂O₃.

A final aspect of this research is the translation of research to commercial application and photocatalytic processes and reactors will be developed with close ties to industry to degrade pollutants relevant to Australia (Figure 1).

Hydrogen production via photocatalytic water splitting

Hydrogen can be produced directly from water and produces only water when burned, making it a completely renewable and non-polluting fuel source that could replace fossil fuels. However, current methods to produce hydrogen requires a significant amount of energy and it is still not economically competitive with oil and gas.

My research aims to produce light absorbing materials which can produce hydrogen (H₂) from water (H₂O) using only energy from sunlight to drive the reaction.

To achieve this, We prepare metal oxides which absorb light, store the energy, and then use the energy to split water. This process is enhanced with co-catalysts to drive hydrogen evolution or oxygen evolution. These co-catalysts are often rare and expensive materials (platinum or rhodium), so we deposit few-atom cluster co-catalysts which we find improve performance and reduce the amount of precious materials used.

My research in reducing the cost of hydrogen production materials is shown in the video:

High resolution transmission electron microscopy (TEM) is used to observe the materials at the atomic scale.