Titanium dioxide nanotubes, key for ultraviolet sensors
UN/DICYT The importance of using tubular titanium dioxide nanostructures lies in that they are cheap, non-toxic and easy to obtain. As demonstrated by tests performed at UNal.
For her Sciences-Physics master’s thesis, Heiddy Paola Quiroz analyzed the usefulness of these sensors as UV ray filters for use in creams, eyeglasses and other solar protection products.
At a laboratory level these sensors may contribute to the study of nanolithography, determining if they are influenced by light emissions. There are already photoconductivity studies in place.
“Titanium dioxide nanotubes can be used in solar cells as photovoltaic devices. There are also other types of sensors that are useful for measuring blood sugar levels, chemicals in solutions and gas sensors,” said Quiroz.
To obtain these materials they first carried out electrochemical etching synthesis, a process which forces titanium oxidation to manufacture the sensor. Furthermore they included ammonium fluoride as aid for voltage samples.
This information along with nanotube morphological and structural characterization and the measurements and diameters of the same were taken into account along with optical properties to become cognizant where the sensors will work.
Another contribution is that they didn’t carry out current but voltage tests, both alternate and continuous. For the first case they produced smooth tubes and for the second nodes appeared on the walls which impact the optical properties of the sensor.
Both measurements are acceptable but the signal rage varies and the specificity needed depends on use. If the voltage is constant the electromagnetic spectrum where the sensors measure light are reduced while as when the voltage is alternate it is larger.
“Therefore we demonstrated that nanotubes are useful for UV sensors and although also useful for other wavelengths, UV signals are stronger, more intense and easier to detect,” said Quiroz.
Now the projection that must be applied is titanium oxide in areas such as biomedical applications where researchers are also working with hydroxyapatite, a bone material for treatments and transplants.
This research project is part of a project which included the Physics and Chemical Engineering Departments under guidance of Professors Anderson Dussán and Hugo Zea.