Direct amorphous-structure analysis: How are surface/bulk structure and activity of titania photocatalyst particles changed by milling?

Abstract

Changes in surface and bulk structures of rutile titania particles induced by braying up to 10 d and post calcination in air at 773K were analyzed by reversed double-beam photoacoustic spectroscopy. The observed energy-resolved distribution of electron traps indicated that the surface was amorphized by braying to give rutile-core amorphous-shell structure and the amorphous layer was partly recrystallized by post-calcination leaving grain boundaries in the surface layers, both of which may cause the observed markedly decreased photocatalytic activities.