Reactivity of Trapped and Accumulated Electrons in Titanium Dioxide Photocatalysis

Abstract

Electrons, photogenerated in conduction bands (CB) and trapped in electron trap defects (Ti ds ) in titanium dioxide (TiO 2 ), play crucial roles in characteristic reductive reactions. This review summarizes the recent progress in the research on electron transfer in photo-excited TiO 2 . Particularly, the reactivity of electrons accumulated in CB and trapped at Ti ds on TiO 2 is highlighted in the reduction of molecular oxygen and molecular nitrogen, and the hydrogenation and dehalogenation of organic substrates. Finally, the prospects for developing highly active TiO 2 photocatalysts are discussed.

Mobile Small Polarons Qualitatively Explain Conductivity in Lithium Titanium Oxide Battery Electrodes

“…This situation seems similar to TiO 2 where the oxygen defect is acting as a charge trapping center. 27,28 However, in LTO one can not directly extract a clear stability trend with the distance to the defect, as positively charged Li-ions also show some influence on the overall stabilities of the polarons. 29 Indeed, our choice of LTO cell allows us to quantify their influence, considering the fact that all our most stable defect configurations are located next to the Li-rich zone situated between L2 and L3.…”

Photocatalytic Nanoparticulate ZrxTi1‐xO2 Coatings with Controlled Homogeneity of Elemental Composition

“…In this connection, time‐resolved TRMC analysis can complement reversed steady‐state double‐beam photoacoustic spectroscopy measurements in elucidation of photocatalytic mechanisms and physical nature of the relevant electron traps, which are still under discussion …”

Smart, Photocatalytic and Self-Cleaning Asphalt Mixtures: A Literature Review

“…The most effective separation of the e − /h + pair is achieved from the Ti defect states and surface Ti-O-Ti sites (or terminal Ti-OH), which can trap the electrons and holes, respectively. In general, oxygen vacancies [26], surface Ti 3+ [27], Ti interstitial or even ions in the lattice or in the near-surface of TiO 2 [28] are responsible by the generation of intra-bandgap energy levels, which are of great importance in retarding the rate of e − /h + recombination and simultaneously can enable the absorption of light by TiO 2 catalyst, not only in the ultraviolet, but also in the visible region of the electromagnetic spectrum [29][30][31].…”