Magnetron-sputtering fabrication of noble metal nanodots coated TiO 2 nanoparticles with enhanced photocatalytic performance

Magnetron-sputtering deposition of coatings onto a flat surface is well established, but coating metal on the curved surface of nanoparticles (NPs) is still challenging. Herein, by using a magnetron sputtering system in which a vibration generator with variable frequency is applied to the sample stage to maintain NPs' dispersity and movability, we successfully deposit noble metal (Au, Ag, Pt) nanodots onto the surface of TiO2 NPs. It is found that the metal nanodots are of a size of 1–6 nm and they are firmly bonded to the TiO2 NPs' surface. The photocatalytic activity of Ag/TiO2 is demonstrated to be 2.7 times that of pure TiO2 under simulated sunlight irradiation. This study creates new opportunities for fabricating excellent NP composite catalysts by liquid-free methods.