Nanoporous Aggregates of ZnS Nanocrystallites
1998 (English)In: Applied organometallic chemistry, ISSN 0268-2605, E-ISSN 1099-0739, Vol. 12, no 5, 327-335 p.Article in journal (Refereed) PublishedText
During the synthesis of ZnS powders by wet chemical precipitation, the formation of nanoporous spheres is observed. The powders have been investigated using thermogravimetric analysis, X-ray diffraction and optical spectroscopies. Nanopore formation can be explained by several stages of growth. The formation of nanoparticles as primary particles is followed by their agglomeration forming secondary particles. These secondary particles are monodispersed spheres with a considerable porosity, because the agglomeration of the nanoparticles is unlikely to be volume-filling. The voids or nanopores formed by this agglomeration process in the secondary particles is estimated to comprise around 35% of the sphere volume. They are mainly filled with water and the residues of the chemical reagents. Water in the pores partially reacts with ZnS and forms hydrated sulphates. The chemical reagents used for the precipitation reactions are also found to be bound to the nanocrystallite's surfaces as ligands in some cases. Depending on the reaction conditions and reagents, the agglomeration of the nanoparticles can also be modified or hindered by the use of complexing agents acting as a sterically stabilizing surface layer on the nanocrystallites. The agglomeration of nanoparticles to larger units being a general phenomenon, this use of complexing agents to control pore formation and agglomerate size should be applicable to other nanocrystalline systems.
Place, publisher, year, edition, pages
John Wiley & Sons, 1998. Vol. 12, no 5, 327-335 p.
Nanocrystallites, Nanopores, Optical transmission spectroscopy, Precipitation, Raman spectroscopy, Thermogravimetric analysis, Transmission electron microscopy, Vibrational spectroscopy, X-ray diffraction, Zinc sulphide
IdentifiersURN: urn:nbn:se:kth:diva-182967DOI: 10.1002/(SICI)1099-0739(199805)12:5<327::AID-AOC725>3.0.CO;2-UISI: 000073820900005ScopusID: 2-s2.0-0001520788OAI: oai:DiVA.org:kth-182967DiVA: diva2:914231
NR 201603312016-03-232016-02-242016-03-31Bibliographically approved