Dataset Information

Suppressing the Photocatalytic Activity of TiO₂ Nanoparticles by Extremely Thin Al₂O₃ Films Grown by Gas-Phase Deposition at Ambient Conditions.

ABSTRACT: This work investigated the suppression of photocatalytic activity of titanium dioxide (TiO₂) pigment powders by extremely thin aluminum oxide (Al₂O₃) films deposited via an atomic-layer-deposition-type process using trimethylaluminum (TMA) and H₂O as precursors. The deposition was performed on multiple grams of TiO₂ powder at room temperature and atmospheric pressure in a fluidized bed reactor, resulting in the growth of uniform and conformal Al₂O₃ films with thickness control at sub-nanometer level. The as-deposited Al₂O₃ films exhibited excellent photocatalytic suppression ability. Accordingly, an Al₂O₃ layer with a thickness of 1 nm could efficiently suppress the photocatalytic activities of rutile, anatase, and P25 TiO₂ nanoparticles without affecting their bulk optical properties. In addition, the influence of high-temperature annealing on the properties of the Al₂O₃ layers was investigated, revealing the possibility of achieving porous Al₂O₃ layers. Our approach demonstrated a fast, efficient, and simple route to coating Al₂O₃ films on TiO₂ pigment powders at the multigram scale, and showed great potential for large-scale production development.

SUBMITTER: Guo J

PROVIDER: S-EPMC5853694 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Suppressing the Photocatalytic Activity of TiO₂ Nanoparticles by Extremely Thin Al₂O₃ Films Grown by Gas-Phase Deposition at Ambient Conditions.

Guo Jing J Van Bui Hao H Valdesueiro David D Yuan Shaojun S Liang Bin B van Ommen J Ruud JR

Nanomaterials (Basel, Switzerland) 20180124 2

This work investigated the suppression of photocatalytic activity of titanium dioxide (TiO₂) pigment powders by extremely thin aluminum oxide (Al₂O₃) films deposited via an atomic-layer-deposition-type process using trimethylaluminum (TMA) and H₂O as precursors. The deposition was performed on multiple grams of TiO₂ powder at room temperature and atmospheric pressure in a fluidized bed reactor, resulting in the growth of uniform and conformal Al₂O₃ films with thickness control at sub-nanometer l ...[more]

PMID: 29364840

Similar Datasets

Project description:Titanium dioxide (TiO2) in the form of thin films has attracted enormous attention for photocatalysis. It combines the fundamental properties of TiO2 as a large bandgap semiconductor with the advantage of thin films, making it competitive with TiO2 powders for recycling and maintenance in photocatalytic applications. There are many aspects affecting the photocatalytic performance of thin film structures, such as the nanocrystalline size, surface morphology, and phase composition. However, the quantification of each influencing aspect needs to be better studied and correlated. Here, we prepared a series of TiO2 thin films using a sol-gel process and spin-coated on p-type, (100)-oriented silicon substrates with a native oxide layer. The as-deposited TiO2 thin films were then annealed at different temperatures from 400 °C to 800 °C for 3 h in an ambient atmosphere. This sample synthesis provided systemic parameter variation regarding the aspects mentioned above. To characterize thin films, several techniques were used. Spectroscopic ellipsometry (SE) was employed for the investigation of the film thickness and the optical properties. The results revealed that an increasing annealing temperature reduced the film thickness with an increase in the refractive index. Atomic force microscopy (AFM) was utilized to examine the surface morphology, revealing an increased surface roughness and grain sizes. X-ray diffractometry (XRD) and UV-Raman spectroscopy were used to study the phase composition and crystallite size. The annealing process initially led to the formation of pure anatase, followed by a transformation from anatase to rutile as the annealing temperature increased. An overall enhancement in crystallinity was also observed. The photocatalytic properties of the thin films were tested using the photocatalytic decomposition of acetone gas in a home-built solid (photocatalyst)-gas (reactant) reactor. The composition of the gas mixture in the reaction chamber was monitored using in situ Fourier transform infrared spectroscopy. Finally, all of the structural and spectroscopic characteristics of the TiO2 thin films were quantified and correlated with their photocatalytic properties using a correlation matrix. This provided a good overview of which film properties affect the photocatalytic efficiency the most.

Dataset Information

Suppressing the Photocatalytic Activity of TiO₂ Nanoparticles by Extremely Thin Al₂O₃ Films Grown by Gas-Phase Deposition at Ambient Conditions.

Publications

Suppressing the Photocatalytic Activity of TiO₂ Nanoparticles by Extremely Thin Al₂O₃ Films Grown by Gas-Phase Deposition at Ambient Conditions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets