“…Titanium dioxide (TiO 2 ) has attracted much attention in recent decades because of its applicability in areas such as pigments, optical sensors, (photo)catalysis, , ferromagnetic Fe–N-codoped TiO 2 nanotubes, , graphene-TiO 2 composites, antimicrobial activity, and optoelectronic devices. − Usually, TiO 2 can be found in the brookite (orthorhombic symmetry), anatase (tetragonal), and rutile (tetragonal) crystalline structureswith the last two being the most common and interesting structures for the abovementioned applications. Because rutile is the most stable phase, the anatase-to-rutile (A–R) phase transformation is an irreversible process that depends, among other factors, on the temperature, pressure, presence of impurities, grain size, synthesis processes, and post-annealing conditions. , Therefore, controlling the TiO 2 phase formation is a challenge to guarantee its final performance in many practical devices.…”