Titanium Dioxide Nanostructures Chemical Sensor

Titanium dioxide (TiO2) nanostructures were grown directly on the sensitive area of the transducer. A titanium thin film was deposited on 2 · 2 mm2 alumina substrates by RF magnetron sputtering and hydrothermal method was used to achieve TiO2. This method is characterized by the use of different solutions (KOH, NaOH), a not stirred pressure reactor and a heating system. As-prepared samples require an acid treatment followed by a calcination step to obtain pure TiO2 nanostructures. The nanostructured morphology was confirmed by a scanning electron microscope (SEM) and their structural properties were investigated by RAMAN spectroscopy. Obtained samples were used as gas sensors, and their behaviour towards several gaseous species was analysed in a wide range of working temperatures. Measurements were carried out in a test chamber, investigating the change in the electrical conductance due to the surrounding atmosphere.