Formation of Ag nanoparticles on water-soluble anatase TiO2 clusters and the activation of photocatalysis

Ag nanoparticles were directly deposited on anatase TiO2 clusters via a two-step route, which included a 60Co γ-ray irradiation method after acidic peptization of amorphous TiO2. The as-prepared TiO2 clusters could act as effective stabilizers to immobilize Ag nanoparticles reduced in the process of γ-radiolysis. The composite consisted of TiO2 particles with about 5 nm and Ag particles with less than 2 nm in diameter, and it was highly dispersed in aqueous solution and thermodynamically stable. After calcining Ag/TiO2 composites in flowing N2 gas, a largely enhanced photocatalytic activity was verified by photodegradation of methylene blue (MB).