Studies on O2-TiO2 Interplay Toward Unconventional MOX-Based Optodes for Oxygen Detection

Titanium dioxide (TiO2) is a functional semiconductor metal oxide that plays amajor role in themany applicative fields,mostly includingwater remediation, surface functionalization and photoanodes for photoelectrochemical reactors. TiO2 is also one of the known chemoresistive materials that can be adopted as sensitive layers in solid state gas sensors. TiO2 has a peculiarly property in the fact that it exhibits two different photoluminescence (PL) spectra, depending on the crystalline polymorph considered (rutile or anatase), and that the PLemission of these two phases reacts differently as exposed to molecular oxygen (O2).We showsome representative results of this phenomenon, discussing the possibility to exploit it actual applications.