Titanium Dioxide in Photocatalysis

Abstract

TiO 2 -based heterogeneous photocatalysis is a process that develops rapidly in environmental engineering and it is now employed in several industrial domains, including water treatment, air purification, and self-cleaning surfaces. Photocatalysis is a natural phenomenon in which the TiO 2 accelerates a chemical reaction through the action of light, without being altered. The illuminated TiO 2 induces the formation of reactive species, able to decompose by oxidation and/or reduction reactions organic or inorganic substances. The major part of the applications of photocatalysis corresponds to organic oxidation, and it is now considered as one of the Advanced Oxidation Technologies (AOTs), gathering the reactions mainly based on hydroxyl radical (HO • ) chemistry. The development of a system based on photocatalysis requires gathering knowledge of numerous and various scientific domains: physical-chemistry, materials science, catalysis, environmental chemistry, biology, and engineering science. This chapter is therefore designed to give a detailed survey of the different scientific fields concerning TiO

Role of Rare Earth Elements and Entropy on the Anatase-To-Rutile Phase Transformation of TiO2 Thin Films Deposited by Ion Beam Sputtering

“…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 structureswith 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.…”

Photocatalytic Degradation of Estriol Using Iron-Doped TiO2 under High and Low UV Irradiation

“…Titanium dioxide is the most commonly used photocatalyst because of its reasonable optical and electronic properties, good photocatalytic activity, insolubility in water, chemical and photochemical stability, nontoxicity, low cost, and high efficiency in pollutant mineralization [17][18][19][20]. However, the band gap energy (Eg) of TiO2, frequently reported as 3.2 eV [21], restrains the photocatalytic activation to energy sources with a portion of spectrum emission below 387.5 nm [22].…”

Crystallized TiO2 Nanosurfaces in Biomedical Applications

“…Anatase and brookite are meta-stable at the bulk form and readily transform to rutile when heated [ 25 ]. However, at the nanoscale, anatase and brookite are stable due to their smaller surface energy [ 26 ] and transform into the rutile phase only after reaching a certain nanoparticle size (more than 14 nm) [ 22 ].…”