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CATEGORIES:Department of Materials Science &amp\; Metallurgy 
 Seminar Series
SUMMARY:Zirconium and hafnium oxide nanocrystals and oxo c
 lusters - Prof. Jonathan de Roo
DTSTART;TZID=Europe/London:20230302T150000
DTEND;TZID=Europe/London:20230302T160000
UID:TALK196948AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/196948
DESCRIPTION:Colloidal nanocrystals are usually hybrid inorgani
 c-organic objects. They have an inorganic\, crysta
 lline core which is capped by a layer of organic s
 urfactants. Metal oxide nanocrystals find applicat
 ion in solar cells\, batteries\, bio-imaging\, etc
 . On the other hand\, oxo clusters are building bl
 ocks in metal organic Frameworks (MOFs) with excit
 ing catalytic properties. \n\nFirst\, we introduce
  surfactant-assisted synthesis of colloidal nanocr
 ystals and the (undesired) chemistry that can occu
 r with solvents and ligands. Second\, we elaborate
  on the precursor chemistry during the synthesis o
 f zirconium and hafnium oxide nanocrystals. After 
 establishing an E1 elimination mechanism\, we focu
 s on the crystallization mechanism and find that a
 n amorphous phase precedes the crystalline nanopar
 ticles. Third\, we develop a comprehensive picture
  of the surface chemistry of these metal oxide nan
 ocrystals. We establish ligand exchange rules in b
 oth nonaqueous and aqueous media. As such\, we fin
 d the optimal binding moiety for physiological con
 ditions\; nitrodopamine derivatives. Tailoring the
  surface chemistry allows to use hafnium oxide nan
 ocrystals as contrast agent in Computed Tomography
  (CT) imaging. We will discuss both in vivo and ex
  vivo applications of such contrast agents. Finall
 y\, we take the oxo clusters out of the MOF and co
 nsider it an atomically precise nanocrystal. Using
  the same ligands as for nanocrystals\, the cluste
 rs are endowed with the same solubility properties
  and become useful catalysts. The cluster-catalyze
 d reaction has a five times higher rate than the n
 anocrystal-catalyzed reaction. To analyze the solu
 ble clusters\, we use X-ray total scattering and P
 air Distribution Function analysis. \n\nWe thus pr
 esent here a comprehensive overview of oxide nanoc
 hemistry\, focusing on group 4 metals. \n
LOCATION:Goldsmiths 1 &amp\; https://us06web.zoom.us/j/8168
 8365420?pwd=b3RpdHgxNVhWbWQrbXluMUxYNWVtQT09 Meeti
 ng ID: 816 8836 5420 Passcode: 047859
CONTACT:Julie Smith
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