화학공학소재연구정보센터
Inorganic Chemistry, Vol.50, No.20, 9985-9992, 2011
Porous CdTe Nanocrystal Assemblies: Ligation Effects on the Gelation Process and the Properties of Resultant Aerogels
Highly porous CdTe nanoarchitectures (aerogels) were prepared by sol-gel assembly of discrete nanocrystals followed by supercritical CO2 drying. CdTe nano crystal surface functionalization (either phosphine oxide or thiolate) is found to be immaterial to oxidation induced gel formation suggesting that the standard thiolate capping procedure is not a necessary step in the gelation process. On the basis of this observation, and reduction induced dispersion of the gel network, the exposure of reactive sites and the subsequent surface oxidation reaction to form polychalcogenide linkages are key steps in the gelation mechanism. Consequently, CdTe aerogels exhibit similar physicochemical properties, regardless of original ligating functionality. The aerogels are mesoporous, with surface area >100 m(2)/g, and exhibit an optical bandgap of 1.92 eV, consistent with quantum confinement within the 3-D linked network. Photoluminescence is suppressed in the aerogels, but can be partially recovered upon heating.