Semiconductor-Metal Nanocomposites

Dawson A., Kamat P.V. (2001) Semiconductor-metal Nanocomposites. Photoinduced Fusion and Photocatalysis of Gold-Capped Ti02 (Ti02/Gold) Nanoparticles, J. Phys. Chem. B. 105(5), 960-966. 

Cozzoli, P.D., R. Comparelli, E. Fanizza, M.L. Curri, A. Agostiano and D. Laub (2004a). Photocatalytic synthesis of silver nanoparticles stabilized by Ti02 nanorods A semiconductor/metal nanocomposite in homogeneous nonpolar solution. Journal of the American Chemical Society, 126(12), 3868-3879. 

A. Dawson P. V. Kamat, Semiconductor-metal nanocomposites. Photo-induced fusion and photocatalysis of gold-capped Ti02 (Ti02/Au) nanopartides./. Phys. Chem. B 2001, 105, 960-966. 

Granitzer P, Rumpf K, Poelt P, Albu M, Chemev B (2009) The interior interfaces of a semiconductor/metal nanocomposite and their influence on its physical properties. Phys Stat Sol (c) 6 2222... 

Keywords. Dendrimer, Metal nanoparticles, Semiconductor nanoparticles, Nanocomposites... 

Metal sulphide semiconductors/polymer nanocomposites are considered to be highly functional materials with many applications, such as in photoluminescent, photoelectric and non-linear optical materials. The flexibility and processability of polymer matrices can provide good mechanical properties. 

Several assemblies of metal sulphide semiconductors/polymer nanocomposites have been realized by using this method ... 

Zhang N, Liu S, Xu Y-J (2012) Recent progress on metal core semiconductor shell nanocomposites as a promising type of photocatalyst. Nanoscale 4 2227-2238... 

The synthesis of MNCGs can be obtained by sol-gel, sputtering, chemical vapor-deposition techniques. Ion implantation of metal or semiconductor ions into glass has been explored since the last decade as a useful technique to produce nanocomposite materials in which nanometer sized metal or semiconductor particles are embedded in dielectric matrices [1,2,4,23-29]. Furthermore, ion implantation has been used as the first step of combined methodologies that involve other treatments such as thermal annealing in controlled atmosphere, laser, or ion irradiation [30-32]. 

While the variety of NPs used in catalytic and sensor applications is extensive, this chapter will primarily focus on metallic and semiconductor NPs. The term functional nanoparticle will refer to a nanoparticle that interacts with a complementary molecule and facilitate an electrochemical process, integrating supramolecular and redox function. The chapter will first concentrate on the role of exo-active surfaces and core-based materials within sensor applications. Exo-active surfaces will be evaluated based upon their types of molecular receptors, ability to incorporate multiple chemical functionalities, selectivity toward distinct analytes, versatility as nanoscale receptors, and ability to modify electrodes via nanocomposite assemblies. Core-based materials will focus on electrochemical labeling and tagging methods for biosensor applications, as well as biological processes that generate an electrochemical response at their core. Finally, this chapter will shift its focus toward the catalytic nature of NPs, discussing electrochemical reactions and enhancement in electron transfer. 

The formula (11) in view of relations for /ie and /ih describes above-mentioned basic features of size effects in semiconductor crystal. It is important that as against metals, semiconductors show appreciable quantum dimensional effects at the sizes of particles from 3 to lOnm (depending on electronic structure of the semiconductor and sizes of AE0) [20]. Such nanoparticles are usually formed at synthesis of nanocomposite films. 

Similar histograms were determined by TEM for Pb-, Zn-, and Cd-containing nanocomposite PPX films prepared by vapor deposition cryochemical synthesis [85]. The value d of metal nanocrystals in these films is also 5nm. The same approximately size d ( 4.5nm) has been evaluated from Ai/2 of X-ray diffraction peak for semiconductor PbS nanocrystals in PbS-PPX nanocomposite [71]. It should be particularly emphasized that d value of M/SC nanocrystals embedded by cryosynthesis in PPX and C1PPX matrices does not depend on M/SC content as for low loading (0.2-2 vol.% for Ag in PPX and C1PPX [75, 80] and 0.01-1 vol.% for Pb in PPX [85]) and for high loading (5-11 vol.% for PbS in PPX [3, 71, 86]) systems. 

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