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Graphene/silver nanocomposites are synthesized in the presence of sodium hydroxide, with graphene oxide and AgNO3 used as the raw materials. X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), and transmission electronic electron microscope, UV-vis spectrophotometer are used to characterize the obtained composites. Results indicate that the graphene oxide is partically reduced to graphene sheets, silver ions are reduced to silver nanoparticles and distributed on the graphene sheets uniformly. The action temperature, quantity of silver nitrate, adding order of NaOH and the way of mixing precusors have an influence on the silver size and particulate size distribution. The size distribution of Ag nanoparticles is centred at 12 nm under a suitable number of silver ions.

The structure of water molecules encapsulated in single-walled carbon nanotubes (SWCNTs) was studied using a self-consistent charge density functional tight binding method with dispersion correction. The most interesting and important feature observed is the diameter shrinkage of SWCNTs when water chains are confined inside them. The diameter shrinking of SWCNTs may be due to the van der Waals and H-π interaction between water chains and SWCNTs. The binding energy decreases with the increase of the nanotube radius. But when the radius is increased to 6.78 ?, the binding energy is a little increased, and the water chain has changed as a "book-like" structure, which suggests that the weak hydrogen bonding in the isolated water chains is larger than the interaction between water chains and the SWCNTs.

We present a systematical study on the possible stable structures of C60−𝑥Si𝑥(𝑥 = 1-12) fullerenes using firstprinciples calculations combined with Monte-Carlo simulations. The initial fullerenes randomly substituting with silicon atoms are firstly generated and then their total energies are calculated quickly. The ground-state structures are found by the annealing process where Si atoms exchange their positions with C atoms. The stable structures are finally obtained through first-principles calculations with high precision. For the cases with a small amount of Si atoms (𝑥≤4), results similar to those report previously are achieved. Some new stable Si-doped fullerenes with more Si atoms are also predicated. The results show that Si atoms in the C60−𝑥Si𝑥(𝑥≤4) fullerenes have a trend of segregation with C atoms. The minimum-energy structure changes from a chemical unstable state to a chemical stable state when 𝑥≥8.