Is Photooxidation Activity of {001} Facets Truly Lower Than That of {101} Facets for Anatase TiO₂ Crystals?

The effect of particle size and active surfaces on photoreactivity of TiO₂ crystals is investigated in this report. The clarification of highly active surfaces is the key to understanding the photoreactivity of anatase TiO₂ crystal and also to morphological control of photocatalysts with well-defined crystal facets. The anatase TiO₂ single crystals with different percentage of {001} facets in uniform size, as well as anatase TiO₂ single crystals with different particles size in same percentage of {001} facets, are synthesized by carefully controlling the synthesis parameters. Their photooxiation reactivity results indicate that the underlying dominant factor for photooxidation activity of anatase TiO₂ crystals is particle size. The photooxidation activity of {001} facets is greater than that of {101} facets when the crystals size of anatase TiO₂ is identical. This work would be beneficial for better understanding the different photocatalytic performance of different facets of metal oxide crystals in photoreactivity processes