| 1. |
- Cieslak, Anna M., et al.
(författare)
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Ultra long-lived electron-hole separation within water-soluble colloidal ZnO nanocrystals : Prospective Applications For Solar Energy Production
- 2016
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855. ; 30, s. 187-192
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Tidskriftsartikel (refereegranskat)abstract
- Zinc oxide was one of the first semiconductors used in dye-sensitized solar cells but its instability in aqueous media precludes its use for large-scale applications. Herein, we report on a novel ZnO nanocrystal material derived by an organometallic approach that is simultaneously stable and soluble in water due to its carboxylate oligoethylene glycol shell strongly anchored to the inorganic core by the head groups. The resulting unique inorganic core-organic shell interface also stabilizes the photo-generated hole, leading to a dramatic slowing down of charge recombination, which otherwise is a major hurdle in using nanostructured ZnO.
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| 2. |
- Sá, Jacinto, et al.
(författare)
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Synthesis, Characterization and Application to Catalysis of ZnO Nanocrystals
- 2015
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Ingår i: Chemical Science Review and Letters. - 2278-6783. ; 4:14, s. 735-745
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Tidskriftsartikel (refereegranskat)abstract
- Nano-metal oxides gained considerable importance due to theirdistinct catalytic activities in various organic transformations dueto the combination of high surface area and unusually reactivemorphologies. ZnO is an important semiconductor material, witha wide range of applications including: pigments, cosmetics,chemical sensors, solar cells and optoelectronics. Additionally,ZnO nanocrystals (NCs) are an eco-friendly, non-toxic,inexpensive and commercially available material, which isstarting to be exploited as a potentially economical and highlyefficient catalyst for a plethora of organic reactions. Herein, wereview fundamentals of ZnO NCs preparation and the recentdevelopments in reactions catalysed by ZnO NCs with specialfocus on solventless transformations.
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| 3. |
- Szlachetko, Jakub, et al.
(författare)
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Hidden gapless states during thermal transformations of preorganized zinc alkoxides to zinc oxide nanocrystals
- 2018
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Ingår i: Materials Horizons. - : Royal Society of Chemistry (RSC). - 2051-6347 .- 2051-6355. ; 5:5, s. 905-911
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Tidskriftsartikel (refereegranskat)abstract
- Zinc oxide (ZnO) is one of the most versatile semiconductor materials with multifarious potential applications. Easily accessible alkylzinc alkoxides have been widely exploited as single-source precursors of ZnO-based nanomaterials but their multi-step decomposition pathways have not been understood in detail. Herein, the formation mechanism of ZnO nanocrystals via solid-state thermal decomposition of a model pre-organised alkylzinc alkoxide precursor, i.e. [tBuZn(mu(3)-OtBu)](4), is elucidated using in situ valence-to-core X-ray emission (v2c-XES) and high energy resolution off-resonant spectroscopy (HEROS) in conjunction with theoretical calculations. Combination of in situ spectroscopic measurements and theoretical simulations indicates that the precursor structural evolution is initiated by the homolytic cleavage of the R-Zn bond, which leads to the formation of a transient radical ([center dot Zn(mu(3)-OR)][RZn(mu(3)-OR)](3)) species, which is responsible for the initial decomposition process. The ensuing multistep transformations involve the formation of intermediate radical zinc oxo-alkoxide clusters with gapless electronic states. Hitherto, the formation of clusters of this type has not been considered either as intermediate structures en route to a semiconductor ZnO phase or as potential species accounting for various defect states of ZnO NCs, particularly the singly charged oxygen vacancy, V-o(+).
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