BEGIN:VCALENDAR VERSION:2.0 PRODID:-//jEvents 2.0 for Joomla//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT UID:7696ebabc67c248af33e9cc7083625e5 CATEGORIES:Seminar CREATED:20180426T122526 SUMMARY:Professor Audrey Moores DESCRIPTION:
Friday May 4, 2018
10:30am, BME Room 116
Hosted by Professor Teddy Asefa
“S olvent-free Synthesis of Nanoparticles and Surface Plasmon Resonance Enhanc ed Hydrogenation Catalysis”
Nanomaterials are intensely researched fo
r their powerful properties applicable in the broad fields of medicine, ele
ctronics, optics and catalysis. Because metal NPs are kinetically
stab
ilized materials, their synthesis often relies on the use of excess solvent
s, additives and strong reducing agents, which limits their easy scale-up.
To address this shortcoming, we
developed a novel synthetic method for
the scalable production of metal and metal sulfide NPs under solvent-free,
mechanochemical conditions. The synthesis of Au NPs provided access t
o monodisperse and ultra-small NPs in the size range of 1–4 nm, without ext
ernal reducing agents or bulk solvents. Using lignin as a biomass-base
d reducer, we could access embedded NPs of Au, Ru, Pd and Re. With Ag, this
method gave access to antibacterial filters in a simplified fashion.
Finally Bi2S3 nanoparticles were easily synthesized by mechanochemical
activation from molecular precursors and cysteine as a sulfur source, 
;followed by aging to afford X-ray active materials, applicable to cancer d
etection. Besides, we have employed silver nanocubes for hydrogen acti
vation and hydrogenation of ketones and aldehydes via irradiation at 405 nm
, corresponding to the position of the plasmon band of the nanocubes.5
Exposure to other wavelengths, or absence of light failed to provide activ
ity thus proving the plasmonic effect. Compared to other catalytic systems,
the plasmonically activated catalyst provides access to primary and second
ary alcohols using milder conditions, in a highly atom economical fashion.
Plasmonic catalysis of the oxidation of aldehyde to carboxylic acid was als
o demonstrated.
Friday May 4 , 2018
10:30am, BME Room 116
Hosted by Professor Teddy Asefa
“Solvent-free Synthesis of Nanoparticles and Surface Plasmon Resonance Enhanced Hydrogenation Catalysis”
Nanomaterials ar
e intensely researched for their powerful properties applicable in the broa
d fields of medicine, electronics, optics and catalysis. Because metal NPs
are kinetically
stabilized materials, their synthesis often relies on
the use of excess solvents, additives and strong reducing agents, which lim
its their easy scale-up. To address this shortcoming, we
developed a n
ovel synthetic method for the scalable production of metal and metal sulfid
e NPs under solvent-free, mechanochemical conditions. The synthesis of Au N
Ps provided access to monodisperse and ultra-small NPs in the size ran
ge of 1–4 nm, without external reducing agents or bulk solvents. Using
lignin as a biomass-based reducer, we could access embedded NPs of Au, Ru,
Pd and Re. With Ag, this method gave access to antibacterial filters
in a simplified fashion. Finally Bi2S3 nanoparticles were easily synthesize
d by mechanochemical activation from molecular precursors and cysteine
as a sulfur source, followed by aging to afford X-ray active material
s, applicable to cancer detection. Besides, we have employed silver na
nocubes for hydrogen activation and hydrogenation of ketones and aldehydes
via irradiation at 405 nm, corresponding to the position of the plasmo
n band of the nanocubes.5 Exposure to other wavelengths, or absence of ligh
t failed to provide activity thus proving the plasmonic effect. Compared to
other catalytic systems, the plasmonically activated catalyst provides acc
ess to primary and secondary alcohols using milder conditions, in a highly
atom economical fashion. Plasmonic catalysis of the oxidation of aldehyde t
o carboxylic acid was also demonstrated.