RT Journal Article
SR Electronic
A1 Štaffenová, Nikoleta
A1 Bajtošová, Lucia
A1 Chochoľaková, Elena
A1 Hanuš, Jan
A1 Cieslar, Miroslav
T1 Formation of TiO2 Hollow Nanoparticles Studied by in Situ TEM
JF Manufacturing Technology Journal
YR 2025
VO 25
IS 6
SP 788
OP 793
DO 10.21062/mft.2025.079
UL https://journalmt.com/artkey/mft-202506-0004.php
AB Hollow TiO₂ architectures are attractive for catalysis and sensing but typically produced by wet-chemical templating and sub-micron sizes. Here we demonstrate a dry, template-free route to nanoscale hollow shells by combining DC magnetron sputtering with in situ TEM heating. Heating to 900 °C produces sub-50 nm TiO₂ hollow shells with ~20 nm compact walls via oxidation-driven Kirkendall hollowing. The oxide evolves from amorphous at low temperature to anatase locally (~500 °C) and then to a rutile/brookite mixture by ~600 °C. The hollow architecture withstands a temperature of 900 °C without measurable sintering. Beam-off regions and ex-situ air annealing show the same hollowing and phase evolution, confirming a thermally driven, not beam-induced, transformation reproducible in air.