Simple Size Control of Spherical Titania Nanoparticles with KCl

Titania nanoparticles (TNPs) that are already in widespread used in our daily lives as white pigments and sunscreen materials have attracted much attention for their possible applications in various fields, such as photonic band materials, gas sensing, solar cells, batteries, and photocatalysts.1-10 Among other properties, the great photocatalytic properties of TNPs have been actively investigated to remove organic pollutants.10, 11 The photocatalytic properties of TNPs come from their wide bandgap of approximately 3.4 eV and band position. Under UV irradiation, an electron of the valence band is excited to the conduction band, generating an electron–hole pair. The electron and hole migrate to the surface of the TNPs to participate in possible chemical reactions. Typically, the water absorbed on the surface of titania can participate in a redox reaction to generate reactive oxygen specie…