Photochemical formation of semiconducting nanostructures

Abstract

Existing data on photochemical and photocatalytic approaches to the formation of semiconducting nanoparticles and also binary semiconducting nanostructures and nanocomposites of semiconductors with metals and polymers are reviewed. The nature of the effect of irradiation on the synthesis and properties of the obtained nanostructures and the possibility of photocatalytic control of the structural and spectral parameters of nanostructural semiconducting systems are examined.The accumulation of data on the properties of semiconducting (SC) nanomaterials, which has occurred particularly rapidly in the last 7-10 years, has opened up ever more alluring prospects for their application as light-sensitive and light-emitting components in nanophotonics [1-3], nanophotocatalysis [2,[4][5][6][7], biosensorics [8][9][10][11], and other important fields. The possibility of practical utilization is an important factor that has stimulated the search for and study of the processes involved in the formation of nanomaterials. On this account an enormous number of publications have now accumulated on the improvement of existing and development of new methods for the synthesis of semiconducting nanoparticles and nanostructures (e.g., see the reviews [6, 12-15]). A special position among them is occupied by methods based on photochemical transformations conducted either for the purpose of synthesis and directing it along a desired path or for improving the characteristics of nanostructures produced by other methods.Photochemical methods of synthesis have proved more effective than the production of nanomaterials by traditional synthetic approaches, and in a number of cases only they make it possible to achieve the assigned aim. For this reason the synthesis of semiconducting nanostructures and their modification under the conditions of photoirradiation are constantly attracting the attention of investigators, and the number of publications devoted to these questions is constantly increasing. We note, however, that they nevertheless remain disjointed.In view of the foregoing an attempt is made in the present article to organize existing data, to identify the most important directions for research and development, and thus to assess the current state of development of photochemical approaches to the formation of semiconducting nanostructures. Analysis of data on the photochemical formation and post-synthesis photochemical treatment of semiconducting nanostructures and multicomponent nanocomposites, including the nanoparticles of metals and polymers in addition to semiconductors, showed that in spite of the variety and diversity of the proposed approaches all the papers can be ascribed to only three courses: synthesis, synthesis control, and changing the characteristics of the semiconducting nanostructures. For this reason in this review photochemical approaches to the synthesis of nanoparticles of metal chalcogenides, binary semiconducting nanostructures, and nanocomposites consisting of semiconducting and conducting polymers are examin...

Photochemical synthesis of size-tailored hexagonal ZnS quantum dots

“…The study of photochemical routes to chalcogenides has also been addressed. [17][18][19][20][21][22][23][24][25] Ketyl radicals generated photochemically using aromatic ketones have been employed for the etching of surface material in CdSe and CdSe/ZnS NPs. 26,27 However, in spite of important practical advantages, the photochemical routes have not been extensively exploited for the production of ZnS QDs.…”

Ferritin as a model for developing 3rd generation nano architecture organic/inorganic hybrid photo catalysts for energy conversion

“…Metal oxides of other transition metals possess the same photochemical properties and also undergo photo corrosion. 49,50 Metal oxide nanoparticles are not soluble but when metal oxides are encapsulated inside ferritin, the protein shell, which is soluble, allows the metal oxides to be dispersed in solution. Relatively high concentrations of the metal oxides can be achieved when solubilized in ferritin.…”

Photoassisted formation of CuxS-based cathodes for CdS-sensitized solar cells with S2−/Sx2− electrolyte

“…The range of metal chalcogenide compounds that can be formed on the surface of titania or zinc oxide by photocatalytic transformations is quite broad 6,8,9 and it also includes those semiconductors that can be used as the active components of the counter-electrodes in the SSSCs such as Cu x S, 7,12 Ag 2 S, 11 PbS, 14 MoS 2 , 19 and Bi 2 S 3 . 20 In particular, copper sulfide, a "classic" cathode material in the SSSCs, [21][22][23] can be obtained as a product of a photocatalytic reaction with the participation of sulfur, CuCl 2 and ethanol on the surface of TiO 2 12 or, alternatively, via the sulfidation of the photocatalytically deposited copper NPs.…”