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Titanium disulfide
Titanium disulfide is a golden, yellow solid material with high electrical conductivity. Titanium disulfide is commonly used as a semiconductor in lithium and magnesium battery cathodes (TiS2 nanotubes paper), as its conductivity is increased when layers are formed with electron-donors such as alkali metals in a process called intercalation (chemistry). TiS2 has interesting material properties. The hexagonal close-packed structure is analogous to Cadmium iodide (CdI2) structure, with half of the octahedral holes filled with a cation. This is a common structure of d-metal halides and d-metal chalcogenides

Material Properties
1. high pressure studies support semimetal, not semiconductor

2. no significant change in density of state at Fermi level up to 20 GPa

3. transport properties change at 15GPa

4.

Nanostructures
Many types of titanium disulfide nanostructures can be achieved through similar methods. Nanotubes, nanoclusters, whiskers, nanodisks, thin films and flower-like structures have been described. 1.	Synthesis of nanotubes

2.	Synthesis of nanoclusters

a. nanoclusters=quantum dots, unique electronic and chem.. properties beacause of quantum confinement and very large surface/volume ratios.

b. structure of common form: hexagonal layered structure; sheet of hcp metal between two sheets of hcp chalcogens (atoms within this layer are covalently bonded). Each metal ion is surrounded by 6 chalcogens as an octahedral structure.

c. nanoparticles achieved using micelle structures that create a template for the correct size growth. If nucleation is a controlled step, the desired size products can be achieved in a narrow distribution.

d. The following reagents were used as received: titanium tetrachloride (TiCl4, Aldrich), iron(II) sulphide 99% (Sigma, Australia), concentrated hydrochloric acid (32% w/w) (Asia Pacific Speciality Chemicals Limited, Australia), tridodecylmethyl ammonium iodide (TDAI).

3.	Synthesis of whiskers

a.	Synthesis on Nickel coated Silicon wafers via simple vapor transport deposition at 630 degrees C

b.	Properties of whiskers (Single crystalline, exact stoichiometric composition)

c.	Theoretical and experimental opportunites for similar whisker arrays

4.	Synthesis of nanodisks

a.	Physical properties of TiS2 dependent on number of layersdisks enhance properties

b.	The orbital overlap of the atoms on the surface of each layer can have a significant influence on the resultant bandgap structure and this effect will be more significant as the number of layers decreases. Thus, it was theoretically anticipated that single-layered titanium sulfide would have semiconducting properties, while the bulk material would be semimetallic. TiCl4 and S, varying times, oleylamine solvent, 110degrees C

5.	Synthesis of thin films

6.	Fullerenes

a. fullerene=closed-cage nanoparticles, synth using gas-phase synthesis

b. perfectly spherical structure, diameter btwn 60 and 80 nm, consisting of about 90 concentric layers.

c. spherical shape provides ‘rolling friction with a reduced friction coefficient and wear’

7.	Synthesis of flower-like structures

a.	control of injection temperature changes 2D to 3D(higher temp for 3D)

b.	final morphology can be controlled by nucleation sites’ initial properties (flakes-instant nucleation,  flowers-spherical nucleus)

c.	synth: titanium tetrachloride with elemental sulfur in solvent 1-octadecene

d.	highest surface area-flowers, better for hydrogen storage than flakes or even nanotubes