In situ controllable growth of noble metal nanodot on graphene sheet

A facile and green method was developed for controllable growth of metal nanodot on graphene sheet. Ultrafine metal nanodots with a size of similar to 2.0 nm in a narrow size distribution are uniformly decorated on graphene sheet through a sonolytic followed by hydrothermal reduction route without extra reducing agent. While hydrothermal reduction without sonolytic treatment, metal nanocrystal with a diameter of similar to 18 nm grows on graphene sheet. The size-selective growth of metal nanodots on graphene sheet arises from the higher diffusion barrier in metal ion doped graphene oxide (GO) system formed during sonolytic process and limited the size of growing metal nanodot. X-Ray photoelectron spectroscopy (XPS) spectra suggest there is a size-dependent alternation of electronic structure of metal nanodot on graphene sheet, giving rise to unusual electronic and catalytic properties. The synthetic strategies described here were expanded on the range of metal nanodot/graphene composites, paving new avenues for the nanodot buildup and therefore promoting functionality.