Technique means that titanium dioxide could be better applied

It is claimed the development should make titanium dioxide more efficient in a range of applications, including photovoltaic cells, hydrogen production, anti-microbial coatings, smart sensors and optical communication technologies.

According to a statement, the new technique allows researchers to control the phase of the titanium dioxide by modifying the structure of the titanium trioxide and sapphire substrate.

Titanium dioxide most commonly comes in one of two major phases, meaning that its atoms arrange themselves in one of two crystalline structures.

These phases are anatase or rutile and the arrangement of atoms dictates the material’s optical, chemical and electronic properties. Consequently, each phase has different characteristics.

The anatase phase has characteristics that make it better suited for use as an anti-bacterial agent and for applications such as hydrogen production. The rutile phase is better suited for use in other applications, such as photovoltaic cells, smart sensors and optical communication technologies.

‘Traditionally, it has been a challenge to stabilise titanium dioxide in the desired phase,’ said Dr Jay Narayan, John C Fan Distinguished Chair Professor of Materials Science and Engineering at NC State and co-author of a paper describing the work. ‘The material tends to transform into the anatase phase below 500^oC, and transform into the rutile phase at temperatures above 500^oC.