TY - JOUR
T1 - Suppressing the Photocatalytic Activity of TiO2 Nanoparticles by Extremely Thin Al2O3 Films Grown by Gas-Phase Deposition at Ambient Conditions
AU - Guo, Jing
AU - Bui, Hao
AU - Valdesueiro Gonzalez, David
AU - Yuan, Shaojun
AU - Liang, Bin
AU - van Ommen, Ruud
PY - 2018
Y1 - 2018
N2 - 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
AB - 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
KW - ultrathin Al2O3 films
KW - atomic layer deposition
KW - fluidized bed reactor
KW - photocatalytic suppression
KW - TiO2 pigments
UR - http://resolver.tudelft.nl/uuid:092ee914-625b-4897-85f5-52cdae7ea7e2
U2 - 10.3390/nano8020061
DO - 10.3390/nano8020061
M3 - Article
SN - 2079-4991
VL - 8
JO - Nanomaterials
JF - Nanomaterials
IS - 2
M1 - 61
ER -