Effect of TiO2 Crystallite Diameter on Photocatalytic Water Splitting Rate

Abstract

The effect of (Pt-loaded)TiO2 crystallite diameter (i.e. Scherrer size) on the photocatalytic water splitting rate was investigated. (Pt-loaded)TiO2 powders with a wide range of crystallite diameters from about 16 to 45 nm with a blank region between about 23 and 41 nm were prepared by various annealing processes from an identical TiO2 powder. Water splitting experiments with these powders were carried out with methanol as an oxidizing sacrificial agent. It was found that the photocatalytic water splitting rate was sensitively affected by the crystallite diameter of the (Pt-loaded)TiO2 powder. More concretely, similar steep improvements of photocatalytic water splitting rates from around 15 and a little over 2 to about 30 μmol•m −2 •hr −1 were obtained in the two (Pt-loaded)TiO2 crystallite diameters ranging from 16 to 23 and from 41 to 45 nm, respectively.

Properties of Single Oxygen Vacancies on a Realistic (TiO2)84 Nanoparticle: A Challenge for Density Functionals

“…Titanium dioxide (TiO 2 ), a semiconducting metal oxide, is widely used as a photocatalyst because of its chemical stability, low cost, and nontoxicity. − Both rutile and, especially, anatase nanostructures catalyze the overall splitting of water into molecular hydrogen and oxygen when illuminated with ultraviolet (UV) light. − This photocatalytic process represents a promising clean and sustainable alternative to fossil fuels. , However, applications of TiO 2 show a low quantum yield (QY) and limited harvesting of visible light, which is a direct consequence of the too large band gap of this material. Moreover, fast recombination of photogenerated electron–hole pairs represents an additional problem.…”

Benchmarking the Fundamental Electronic Properties of small TiO2 Nanoclusters by GW and Coupled Cluster Theory Calculations

“…Titanium dioxide (TiO 2 ) nanostructures are key components of many − advanced technological products and processes, for example as photocatalysts for water and air purification and photocatalytic water splitting, − as semiconductors in dye-sensitized solar cells , and as photocatalytic and superhydrophilic coatings for self-cleaning windows. − All these applications depend on a combination of the wettability of TiO 2 by water or other polar solvents, its chemical and mechanical stability in the presence of water and illumination, and the specific optical and/or electronic properties of the TiO 2 nanostructures. TiO 2 is also the archetypal model system for oxide semiconductors where a large amount of fundamental experimental − and computational − studies on the optical, electronic, and photocatalytic properties of both bulk and nanostructured TiO 2 have been performed.…”

“…( ) pq q p p q (11) where ⟨Φ|(1 + Λ) is the left eigenvector of the similarity transformed Hamiltonian H̅ = e −T He T and ̅ a q + and ̅ a p are the similarity transformed creation and annihilation operators a q + and a p ; i.e., The dashed lines correspond to the G 0 W 0 values extrapolated to the complete basis-set limit using approach A (data shown in Table 1). All G 0 W 0 calculations were started from a DFT calculation with the B3LYP XC functional.…”

Mesoporous Spherical TiO2 with Outstanding Photocatalysis under Visible Light

“…The crystal structures of TiO 2 mainly include anatase, rutile, brookite, TiO 2 ‐B. And the photocatalytic effect of anatase TiO 2 is the most remarkable . At present, the modifying methods, such as TiO 2 with different morphologies and metal elements doping, can change the situation .…”