Christa van Oversteeg

PhD Candidate
Employed since: November 2015
Email: c.h.m.vanoversteeg@uu.nl
Room: DDW 4th floor and Ornstein Laboratorium 169

Research

Research

Copper chalcogenide semiconductor nanocrystals for photo- and electrocatalysis

Copper chalcogenides are interesting materials due to their low toxicity, relatively low costs and wide size, shape and composition tunability [1]. In this project the use of copper chalcogenide semiconductor nanocrystals for photocatalysis and electrocatalysis is studied. In photocatalysis, we investigate the hydrogen evolution reaction from H2O in the presence of a sacrificial electron donor. In electrocatalysis we focus on the electroreduction of CO2 and H2O into hydrocarbons and oxygenates. For both photo- and electrocatalysis, the effect of the nanocrystal size, shape and composition on the catalytic performance is investigated.

Supported Cu2-xS nanocrystals are prepared via incipient wetness impregnation followed by a liquid phase sulfidation step. In addition, colloidal synthesis can be used to synthesize particles with a better control over particle size, shape and composition. The colloidal nanocrystals can be used either as colloidal suspension or can be anchored onto a on a catalyst support such as silica (photocatalysis) or carbon (electrocatalysis). The photocatalytic activity is tested by irradiating a suspension of the Cu2-xS nanocrystals in water in the presence of a sacrifical electron donor. The produced H2 can be detected using online gas chromatography. To test the electrocatalytic activity and stability for CO2RR, electrodes are prepared by spraying a thick layer of the supported and colloidal particles on carbon paper and tested using voltammetry and chronoamperometry. The products that are formed are identified using online gas chromatography and 1H-NMR.

Figure 1: a) TEM image of Cu2-xS nanocrystals supported on carbon synthesized by incipient wetness impregnation followed by sulfidation and b) SEM image of Cu2-xS nanocrystals prepared by colloidal synthesis followed by deposition on a carbon support.

[1] W. van der Stam et al., ChemPhysChem 17, 559-581 (2016)

C.V.

C.V.

September 2013 – August 2015:
Master in Nanomaterials: Chemistry & Physics (Honours)
Institute: Utrecht University, the Netherlands
Master thesis: ‘Using X-ray spectroscopy to study the reduction and oxidation sensitivity of cobalt and nickel promoter species in conventional HDS catalysts.’
Research group: Inorganic Chemistry & Catalysis, Utrecht University
Supervisor: Prof. dr. F.M.F. de Groot

Internship: ‘A study of the composition of the electric double layer in battery electrolytes with applied voltage’.
Research group: Ćuk group, University of California, Berkeley
Supervisor: Dr. T. Ćuk

September 2010 − July 2013
Bachelor in Chemistry, Institute: Utrecht University
Bachelor thesis: ‘Improving the stability in the methanol synthesis reaction; The impact of drying conditions on the copper particle distribution in a silica-supported copper catalyst.’
Research group: Inorganic Chemistry & Catalysis, Utrecht University
Supervisor: Prof. Dr. P.E. de Jongh

Publications

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Samarai, Al M; van Oversteeg, C H M; Delgado-Jaime, M U; Weng, T -C; Sokaras, D; Liu, B; van der Linden, M; van der Eerden, A M J; Vogt, E T C; Weckhuysen, B M; de Groot, F M F

Nature of cobalt species during the in situ sulfurization of Co(Ni)Mo/Al<inf>2</inf>O<inf>3</inf> hydrodesulfurization catalysts Journal Article

Journal of Synchrotron Radiation, 26 (3), pp. 811-818, 2019, (cited By 0).

Links | BibTeX

Oversteeg, Van C H M; Oropeza, F E; Hofmann, J P; Hensen, E J M; Jongh, De P E; Donega, De Mello C

Water-Dispersible Copper Sulfide Nanocrystals via Ligand Exchange of 1-Dodecanethiol Journal Article

Chemistry of Materials, 31 (2), pp. 541-552, 2019, (cited By 1).

Links | BibTeX

Oversteeg, Van C H M; Doan, H Q; Groot, De F M F; Cuk, T

In situ X-ray absorption spectroscopy of transition metal based water oxidation catalysts Journal Article

Chemical Society Reviews, 46 (1), pp. 102-125, 2017, (cited By 24).

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