Cd nanowires

Routkevitch D, Bigioni T, Moskovits M, Xu JM (1996) Electrochemical fabrication of CdS nanowire arrays in porous anodic aluminum oxide templates. J Phys Chem 100 14037-14047... 

Suh JS, Lee JS (1997) Surface enhanced Raman scattering for CdS nanowires deposited in anodic aluminum oxide nanotemplate. Chem Phys Lett 281 384-388... 

In contrast to nanowires synthesized by the pressure injection method, nanowires derived electrochemically are typically polycrystalline with no preferred crystal orientation. However, some exceptions occur. For example, polycrystalline CdS nanowires fabricated by ac electrodeposition in anodic alumina were shown to have a preferred wire growth orientation along the c axis (Routkevitch et al., 1996). Recently, Xu et al. (2000a, 2000b) prepared... 

Fig. 22 TEM images of (a) CdS nanowires (b) CdSe nanotubes obtained by using Triton 100-X as the surfactant. Inset in (a) shows the SAED pai-lern of the CdS nanowires. Reprinted with permission from C. N. R. Rao, A. Govindaraj, 1 . L. Dccpak, N. A. Gunari and M. Nath, Appl. Phys. Leu., 2001,78, 1853. 2001, American Institute ofPhysics.

By using polymer-controlled growth in ethylenediamine at 170°C, very long CdS nanowires (100px40 nm) were synthesized (Fig. 9a) [36]. Cadmium sulfide with different morphologies, such as nanoparticles and nanorods (Fig. 9b) [39], peanut-like nanostructures [37] and hollow nanospheres [38] (Fig. 9c) were prepared via solvothermal routes. 

Figure 9. (a) TEM image (left) and SAED pattern (right) of CdS nanowires. 

Fan HM, Fan XF, Ni ZH, Shen ZX, Feng YP, Zou BS (2008) Orientation-dependent Raman -spectroscopy of single wurtzite CdS Nanowires. J Phys Chem C 112 1865-1870... 

Fig. 7.27. XRD pattern, TEM image (insert) of the CdS nanowires prepared by precursor decomposition in organic solvent.

Mukhetjee PK, Chakravorty D (2004) Growth of CdS nanowires using Na-4 mica as template. J Appl Phys 95 3164-3169... 

Using porous anodic aluminium oxide films, Routkevitchand associates electrodeposited very thin CdS nanowires [49]. The alumina membranes were typically 1 - 3-pm thick with pore sizes ranging from 9 to 35 nm. The CdS was electrodeposited, using ac electrodeposition, from a DMSO solution containing CdCl2 and elemental S. The porous alumina, as anodized, was separated from the A1 by a dense oxide... 

The same technique to form CdS nanowires, only employing dc electrodeposition, has been used by Xu and associates [52]. In this case, the A1 was etched away and a silver film evaporated on the membrane. The wires in this case were textured with the (10.1) plane parallel to the membrane surface [in contrast to the ac deposition where the (00.1) plane grew parallel to the surface]. This technique was extended to CdSe and CdTe nanowires [53]. 

This group also deposited CdS nanowires in porous alumina templates using an aqueous solution containing CdC and thioacetamide at pH = 4.6 [54]. This deposition is actually an electrochemicaUy induced chemical solution deposition initiated by local pH changes caused by electrolysis [55]. In this case, the wires... 

Nickel sulfide nanoparticles synthesized by Guo et al. also showed efficient photocatalytic activity in the degradation of Congo Red under visible-light irradiation. The NiS nanoparticles were by a hydrothermal method. A solution of nickel salt, sodium hydroxide and thioacetamide was sealed in a Teflon lined reactor and heated in an oven for 160 °C for 24 hr. After cooling the product was filtered and washed with water and ethanol. CdS nanowires have been used as ID nanoscale substrates for the growth of NiS nanoparticles by a solution phase method.The step involves the synthesis of the CdS nanowires by a solvothermal route. The as-prepared CdS nanowires and NiCla HaO were dissolved in ethanol and loaded into a Telfon autoclave. 

Bashouti M, SalaUia W, Brumer M, Zussman E, Lifshitz E (2006) Alignment of colloidal cds nanowires embedded in polymer nanofibers by electrospinning. ChemPhysChem 7 102-106... 

Other Electrochemical Approaches CdS has also been prepared from aqueous solutions by other methods, with electrodeposition as an important step. CdS nanotubes have been formed by the self-assembly of CdS nanowires that were prepared by electrode-positing Cd into an AAO (anodic aluminum oxide) template followed by sulfurization [25]. A hybrid electrochemical/chemical (E/C) method was employed to synthesize epitaxially oriented CdS on graphite surfaces [26], which involves the electrodeposition of Cd, the conversion of Cd to Cd(OH)2, and the formation of CdS via the displacement of OH by S . Another E/C method in which H2S was used as the sulfur source and reacted with electrodeposited Cd at 300 °C was reported in the preparation of CdS/S core-shell nanoparticles [27]. 

Similar work has been reported by Bard and co-workers where CdS nanoparticles were attached to a gold substrate using hexanedithiol (121). Using this method, it is possible to deposit multilayers that form an addressable three-dimensional quantum dot structure. Template methods have been used to deposit semiconductors of various shapes and sizes. For example, Li demonstrated the use of anodic aluminum oxide (AAO) templates to deposit CdS nanowires with a large aspect ratio (122). 

Fig. 1 Examples of morphologies of semiconductor nanostructures, (a) metal assisted Si etching and formation of Si-NWs. Electrochemical formation of (b) microporous silicon, (c) ZnO nanorods, (d) porous CdSe using porous alumina template, (e) CdTe nanowires using alumina template, (1) CdS nanowires using alumina template, (g) mesoporous Xi02 film using doctor blade method, (h) self-ordered anodic Xi02 nanotubes and (i) cross section image of the same Xi02 nanotubes (reproduced with permission from Ref. 8,27,28,45 8).

Jin J, Yu J, Liu G, Wong PK (2013) Single crystal CdS nanowires with high visible-light photocatalytic H2-production performance. J Mater Chem A 1 10927-10934... 

Weng B, Liu S, Zhang N, Tang Z-R, Xu Y-J (2014) A simple yet efficient visible-light-driven CdS nanowires-carbon nanotube ID-ID nanocomposite photocatalyst. J Catal 309 146-155... 

Liu S, Weng B, Tang Z-R, Xu Y-J (2015) Constructing one-dimensional silver nanowire-doped reduced graphene oxide integrated with CdS nanowire network hybrid structures toward artificial photosynthesis. Nanoscale 7 861-866... 

Han B, Liu S, Xu Y-J, Tang Z-R (2015) ID CdS nanowire-2D BiV04 nanosheet heterostructures toward photocatalytic selective fine-chemical synthesis. RSC Adv... 

Lin S, Yang M-Q, Xu Y-J (2014) Surface charge promotes the synthesis of large, flat structured graphene-(CdS nanowire)-Ti02 nanocomposites as versatile visible light photocatalysts. J Mater Chem A 2(2) 430-440... 

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