Nitrogen-doped TiO2 (N−TiO2) nanocatalyst with spherical shape and homogeneous size has been synthesized through a chemical method using TiCl3 as precursor. The light absorption onset shifts from 380 nm on pure TiO2 to the visible region at 550 nm with N−TiO2. A clear decrease in the band gap and the nitrogen 2p states on the top of the valence band on N−TiO2 (compared to TiO2) is deduced from the optical absorption spectroscopy results. The chemical nature of N has been evolved as N−Ti−O in the anatase TiO2 lattice as identified by X-ray photoelectron spectroscopy (XPS). Photocatalytic decomposition of methylene blue has been carried out both in the UV and in the visible region and N−TiO2 shows higher activity than the Degussa P25 TiO2 photocatalyst in the visible region.

Hexagonal fullerene (C60) nanosheets have been prepared using a liquid−liquid interfacial precipitation method. The size of the hexagonal nanosheets can be tuned appropriately by selecting proper solvent for the interfacial precipitation. The prepared C60 nanosheets are porous, very thin, and foldable in nature.

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As a highly anticipated technique for bottom-up nanotechnology, i.e., shape control of pure functional molecules, we here report controlled formation of two-dimensional (2D) objects such as hexagons and rhombi and their selective shape shifting into one-dimensional (1D) rods through solvent-dependent changes of crystal lattice, all from pure C(60). Uniformly shaped rhombi and hexagons were obtained at tert-butyl alcohol/toluene and i-propyl alcohol/CCl(4) interfaces, respectively. In addition, exposure of these 2D nanosheets to water induced selective transformation into 1D nanorods. Nanorhombi were converted to short nanorods upon exposure to water. This shape shift is accompanied by changes in crystalline structures from a mixed fcc/hexagonal to pure fcc lattice, the latter of which is almost identical with morphologically similar C(60) nanowhiskers. Metastable nanorhombi which possess a strained mixed crystalline structure metamorphosize into the more stable short nanowhisker (nanorods). In contrast, the stable nanohexagon of a single lattice (and so less strain) does not undergo shape shifting. These results clearly demonstrate controlled formation of 2D nanosheets with various shapes (hexagons, rhombi, etc.) and selective shape shifting to nanorods (short nanowhiskers) all from pure C(60) molecules by very simple solvent treatments.

Ultrathin SnS 2 nanoparticle decorated graphene nanosheet (GNS) electrode materials with delaminated structure were prepared using stepwise chemical modification of graphene oxide (GO) nanosheets at very dilute conditions, followed by a hydrothermal treatment. The chemical modification of the graphene nanosheet surface with Sn ions enables the precipitation of ultrathin nanoparticles. The TEM analysis reveals the SnS 2 nanoparticles are homogeneously distributed on the loosely packed graphene surface in such a way that the GNS restacking was hindered. X-ray photoelectron spectroscopic analysis reveals the bonding characteristics of the SnS 2 on the GNS. The obtained nanocomposite exhibits a reversible capacity of 1002 mAh/g, which is significantly higher than its calculated theoretical capacity (584 mAh/g). Furthermore, its cycling performance is enhanced and after 50 cycles, and the charge capacity still remained 577 mAh/g, which is very close to its theoretical capacity. Due to the synergic effect, the Li-ion storage capacity observed for nanocomposites is much higher than its theoretical capacity. The ultrathin size (2 nm) and dimensional confinement of tin sulfide nanoparticles by the surrounding GNS limit the volume expansion upon lithium insertion, and the nanoporous structures serve as buffered spaces during charge/discharge and result in superior cyclic performances by facilitating the electrolyte to contact the entire nanocomposite materials and reduce lithium diffusion length in the nanocomposite.