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.