Shape transformation and relaxation dynamics of photoexcited TiO2/Ag nanocomposites.
The laser-induced sintering of TiO2 nanoparticles into larger nanospheres is accelerated by adsorbed silver particles. For the same weight fraction of silver, silver nanoparticles of 5 nm in diameter modify TiO2 nanoparticles more effectively than those of 1.5 nm do, suggesting that the photocatalysis of TiO2 nanoparticles as well as their stability is highly dependent on the sizes, the shapes, and the distribution of adsorbed metal nanoparticles. The photoexcited electrons of TiO2 nanoparticles are quenched at trap sites and surface states by transfer to the conduction band of silver, implying that the presence of adsorbed silver nanoparticles enhances the photocatalytic effect of TiO2.
Kim
Mee Rahn
MR
School of Chemistry, Seoul National University, NS60, Seoul 151-742, Korea.
Ah
Chil Seong
CS
Shin
Dongha
D
Lee
Sang Kyung
SK
Lee
Wan In
WI
Jang
Du-Jeon
DJ