Search academic texts

Information × Registration Number 0210U000632, 0107U009671 , R & D reports Title Photochemical synthesis and variation of the properties of semiconductor nanostructures popup.stage_title Head Kuchmii Stepan Yaroslavovich, Registration Date 02-03-2010 Organization L.V.Pysarzhevsky Institute of Physical Chemistry of National Academy of Science of Ukraine popup.description2 Objects of study - nanoparticles and nanocomposites of semiconductors stabilized in colloidal solutions, photochemical and photocatalytic processes. The aim of the project - development of the physicochemical basis of forming light-sensitive multicomponent semiconductor nanostructures and metal-semiconductor nanocomposites with high functional properties and means of photochemical control of characteristics of semiconductor nanocrystals (the nanoparticle size, photoluminescence yield, photocatalytic activity, etc.). Experimental methods - stationary and pulse photolysis, absorption spectroscopy in UV and visible range, luminescence and dinamic light scattering spectroscopy, X-ray diffraction, microscopy. Optical and luminescence properties of photocharged ZnO nanoparticles were studied. Influence of the photoinduced charging of ZnO nanoparticles on the parameters of luminescen bands was shown to be a consequence of size dispersion of zinc oxide nanoparticles. Photocatalytic reduction of NaAuCl4 by ethanol with the participation of ZnO nanoparticles was studied. It was shown that after the termination of illumination the gold and ZnО nanoparticles remain in a charged state for a long time, the fact indicating high capacity of ZnО/Au nanocomposite for storage of an excess negative charge. The new synthesis method to produce luminescent CdS and CdSe quantum dots as well as mixed sulfide-selenide nanostructures in colloidal aqueous polyethyleneimine solutions is proposed. The prepared metal-chalcogenide colloids possess wide luminescence bands in the visible spectral region with the quantum yield of emission approaching 15 - 30 %. It is demonstrated that the luminescence of CdS quantum dots is strongly quenched in the presence of even tiny amounts of heavy metal ions, which can be used for development of high-sensitive luminescent analysis methods. Product Description popup.authors Коржак Ганна Василівна Кучмій Степан Ярославович Раєвська Олександра Євгенівна Строюк Олександр Леонідович Швалагін Віталій Васильович popup.nrat_date 2020-04-02 Close