Core–shell nanoheterodimers: laser-assisted deposition of single bimetallic Au@M (M = Au, Ag, Pd, Pt) nanodots on TiO2 nanoparticles
Abstract
We propose to synthesize well-controlled core-shell nanoheterodimers (NHDs) based on single bimetallic Au@M (M = Au, Ag, Pd, Pt) nanodots (BNDs) grown on bare TiO 2 nanoparticles (NPs) by a two-step laser-assisted deposition. The high photon flux emitted by a focused UV laser triggers nucleation and growth of a single core nanodot (ND) and its size is quantitatively controlled by varying the time exposure and the concentration of gold ions in the solution in the first step. A second laser deposition is performed after adding a new metal precursor to the Au-TiO 2 NHDs thus prepared. Due to the vectorial nature of the first Au-TiO 2 NHDs when photo-excited, and thus the subsequent efficient carrier separation, the second photodeposition strictly takes place on the first gold NDs. Growth is epitaxial for both
Domains
Material chemistry
Origin : Publication funded by an institution