Structure and Ionic Transport Properties of AgI_1–xBr_x within Single-Wall Carbon Nanotubes from Molecular Dynamics Simulation

Abstract

Morphologies of AgI 1−x Br x (0 ≤ x ≤ 1) nanocrystalline structures formed in carbon single-wall nanotubes (SWNT), of diameter d = 11.5−17.6 Å, have been investigated by molecular dynamics simulation. For AgI 1−x Br x in a (10, 10) carbon SWNT (d = 13.54 Å), ionic motion characteristics at different temperatures have been studied. Calculations confirm the experimentally based suggestion that structural differences between AgI and AgBr in carbon SWNTs are less pronounced than in the bulk crystals. According to the simulation results, in tubes taken out from the melt, AgBr and AgI 1−x Br x tend to form hexagonal nanotubes after annealing, similar to those formed by AgI. A superionic state, with significant silver ion mobility against a stable anion sublattice, can be observed in the simulated AgI 1−x Br x @SWNT; the superionic conduction temperature range shifts downward with increasing bromine content. At temperatures below and just above the nanocrystal melting point, ion migration is faster in more bromine-rich AgI 1−x Br x @ SWNT systems, while at T ≥ 1000 K, the composition dependence of ion diffusion coefficients is much less pronounced. Just as in AgI@SWNT systems, the ion transport characteristics change significantly with a transition from single-wall AgI 1−x Br x nanotubes in carbon SWNTs to structures with extra ions in the tube center.

Regulations of silver halide nanostructure and composites on photocatalysis

“…However, as superior photo-sensitive materials with the ability to produce plasmonic metal Ag 0 , the introduction of other elements will destroy the original performance; thus, the first two methods have been rarely applied in AgX. Solid solution of semiconductor nanomaterials constituted by parent AgX materials can not only maintain their original high photocatalytic ability but also construct new composite energy band [251].…”

Encapsulation of cadmium telluride nanocrystals within single walled carbon nanotubes

“…There are many theoretical studies available on the molecular structures encapsulated within SWNTs [18][19][20][21][22][23][24][25][26][27][28] . However, only few theoretical reports are available to model experimentally observed 1-d crystals such as KI 29 , HgTe 30 , CuI 31 , PbI2 32 , Sb2Se3 33 , SnSe 34 , AgI 35 , CdSe 16 and PbTe 17 ). In some cases, HRTEM images of 1-d crystals containing lighter atoms are challenging to demonstrate their structures because of their lower resolution.…”