Dennis Woitassek

Dr. Dennis Woitassek


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
2 February 2022 in Molecules
Verified
Journal Article
Open access
PDF file
DWDennis Woitassek
Dennis Woitassek
SLSwantje Lerch
Swantje Lerch
WJWulyu Jiang
Wulyu Jiang
MSMeital Shviro
Meital Shviro
SRStefan Roitsch
Stefan Roitsch
Christoph JaniakChristoph Janiak
Christoph Janiak
In this study, we present the facile formation of platinum nanoparticles (Pt-NPs) on reduced graphite oxide (rGO) (Pt-NP@rGO) by microwave-induced heating of the organometallic precursor ((MeCp)PtMe3 in different tunable aryl alkyl ionic liquids (TAAIL). In the absence of rGO, transmission electron microscopy (TEM) reveals the formation of dense aggregates of Pt-NPs, with primary particle sizes of 2 to 6 nm. In contrast, in the Pt-NP@rGO samples, Pt-NPs are homogeneously distributed on the rGO, without any aggregation. Pt-NP@rGO samples are used as electrode materials for oxygen reduction reaction (ORR), which was assessed by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The electrochemical surface area (ECSA) and mass-specific activity (MA) increase up to twofold, compared with standard Pt/C 60%, making Pt-NP@rGO a competitive material for ORR.

30 September 2022 in Chemistry
Verified
Journal Article
Open access
PDF file
DWDennis Woitassek
Dennis Woitassek
JMJosé G. Moya-Cancino
José G. Moya-Cancino
YSYangyang Sun
Yangyang Sun
YSYefan Song
Yefan Song
DWDennis Woschko
Dennis Woschko
Christoph JaniakChristoph Janiak
Christoph Janiak
Metal nanoparticles are increasingly gaining interest in the field of heterogeneous catalysis. Here, we present a novel strategy for synthesizing sugar-coated platinum nanostructures (SC-Pt-NS) from the carbohydrates sucrose and D(-)-fructose. In the synthesis from a mixture of H2PtCl6·6H2O, the carbohydrate in an ionic liquid (IL) yielded primary particles of a homogeneous average size of ~10 nm, which were aggregated to hierarchical Pt nanostructures of ~40–65 nm and surrounded or supported by the carbohydrate. These sugar-coated platinum nanostructures present a facile way to support and heterogenize nanoparticles, avoid leaching and enable easier separation and handling. The catalytic activity of the SC-Pt-NS was shown in the hydrosilylation test reaction of phenylacetylene with triethylsilane, where very high turnover frequency (TOF) values of up to 87,200 h−1 could be achieved, while the platinum metal leaching into the product was very low.