Synthesis of ZnO nanostructures by hydrothermal method

Georgiou, P; Kolokotronis, K; Simitzis, J

dc.contributor.author	Georgiou, P	en
dc.contributor.author	Kolokotronis, K	en
dc.contributor.author	Simitzis, J	en
dc.date.accessioned	2014-03-01T01:32:02Z
dc.date.available	2014-03-01T01:32:02Z
dc.date.issued	2009	en
dc.identifier.issn	1662-5250	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/20026
dc.subject	Hydrothermal method	en
dc.subject	SEM	en
dc.subject	XRD	en
dc.subject	ZnO nanostructures	en
dc.subject.other	Amorphous regions	en
dc.subject.other	Aqueous solutions	en
dc.subject.other	Atomic absorption spectroscopy	en
dc.subject.other	Branched structures	en
dc.subject.other	Hexagonal pyramids	en
dc.subject.other	Hydrothermal methods	en
dc.subject.other	Liquid Phase	en
dc.subject.other	Molar ratio	en
dc.subject.other	Non-solvents	en
dc.subject.other	Prismatic structures	en
dc.subject.other	Residence time	en
dc.subject.other	SEM	en
dc.subject.other	SEM image	en
dc.subject.other	Water as solvent	en
dc.subject.other	Wurtzites	en
dc.subject.other	XRD	en
dc.subject.other	XRD peaks	en
dc.subject.other	ZnO	en
dc.subject.other	ZnO nanostructures	en
dc.subject.other	Absorption spectroscopy	en
dc.subject.other	Atomic spectroscopy	en
dc.subject.other	Centrifugation	en
dc.subject.other	Ethanol	en
dc.subject.other	Hydrothermal synthesis	en
dc.subject.other	Lattice constants	en
dc.subject.other	Nanostructures	en
dc.subject.other	Nonionic surfactants	en
dc.subject.other	Organic solvents	en
dc.subject.other	Polyethylene glycols	en
dc.subject.other	Polyethylene oxides	en
dc.subject.other	Scanning electron microscopy	en
dc.subject.other	X ray diffraction	en
dc.subject.other	Zinc	en
dc.subject.other	Zinc oxide	en
dc.subject.other	Zinc sulfide	en
dc.subject.other	Amorphous materials	en
dc.title	Synthesis of ZnO nanostructures by hydrothermal method	en
heal.type	journalArticle	en
heal.identifier.primary	10.4028/www.scientific.net/JNanoR.6.157	en
heal.identifier.secondary	http://dx.doi.org/10.4028/www.scientific.net/JNanoR.6.157	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	ZnO was synthesized by the hydrothermal method using proper aqueous solutions of ZnCl2 and NaOH, as the main raw materials, corresponding to the molar ratio of Zn2+ : OH- = 1 : 20 (solution 'A'), and a proper proportion of water as solvent, ethanol (EtOH) as non solvent and polyethylene glycol (PEG) as nonionic surfactant (solution 'B'). The reaction takes place in an autoclave at 200 degrees C for a defined period of time (1-20 h). The solid ZnO products received after centrifugation, washing and drying were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The percentage of unreacted Zn present after the reaction in the liquid phase (incumbent solution) was determined by Atomic Absorption Spectroscopy. The parameters of processing (i.e., temperature, pressure, residence time) and the raw materials parameters (i.e. proportion of Solution 'A'/mL H2O + mL EtoH, amount of PEG) influence the morphology and the dimensions of the product. Increasing the residence time from 1 h -> 3 h -> 20 h, the amorphous regions illustrated in SEM images are decreased and the number and dimensions of the obtained single or branched rods of the final product are increased. Avoiding the use of additional water, i.e. the denominator in the aforementioned ratio, mL, water, is equal to zero, but simultaneously using ethanol, the ZnO material is mainly amorphous. Increasing the amount of the additional water without ethanol, no amorphous material is observed and single rods or flowerlike/starlike structures having ends of regular hexagonal pyramid structure, are formed. Increasing the proportion of PEG, many flowerlike or starlike branched structures having ends of regular hexagonal prismatic structure, are formed. The ZnO materials having much of amorphous regions do not show XRD peaks. On the other hand, the crystalline ZnO materials show many XRD peaks, which are indexed and they correspond to the wurtzite-structured (hexagonal) ZnO. Furthermore, the lattice constants alpha and c are determined.	en
heal.publisher	TRANS TECH PUBLICATIONS LTD	en
heal.journalName	Journal of Nano Research	en
dc.identifier.doi	10.4028/www.scientific.net/JNanoR.6.157	en
dc.identifier.isi	ISI:000271239000017	en
dc.identifier.volume	6	en
dc.identifier.spage	157	en
dc.identifier.epage	168	en