Research Topics

Here you find details on the various research topics in the Smarsly group.

Applied electrochemistry: Several metal oxides are of potential interest in diverse applications based on electrochemical processes or charge transport, e.g. as electrode materials in batteries, novel types of solar cells (e.g. TiO2, ZnO), electrochromic materials (WO3, etc.). It is expected that such physico-chemical properties are enhanced/improved if the metal oxide is prepared in the form of nanoparticles or nanopores, in particular as thin homogeneous films. Electrochemical methods (cyclovoltammetry, etc.) are used to understand the influence of nanostructuration on these properties.

Hierarchical Pore Systems: For diverse applications involving mass transport an ideal pore system would be build up in a “hierarchical” fashion: the small nanopores (3 nm – 100 nm, “mesopores”) are located in the walls of larger pores, ideally on the micrometer scale (1 micrometer = 0.000001 m), thus making the larger surface area readily accessible through such bigger pores. Our group tries to develop strategies to generate such “pore hierarchy” by self-assembly strategies, to establish methods to characterize such complex pore systems in the form of powders and also films and finally to study the influence of pore hierarchy on physico-chemical properties (e.g. by means of electrochemisty).
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Ionic Liquids: Ionic liquids have received much attention because of a multitude of interesting properties, among them their ability to dissolve a variety of chemicals and their high boiling point. By contrast, their use as templates and reaction medium for the generation of nanostructures shows also substantial promise. In this project we use ionic liquids to prepare inorganic nanostructures, e.g. metal oxides.

Carbon: “Non-graphitic“ carbon is derived from graphite, which shows a 3D periodic arrangement of “graphenes” (polyaromatic rings of sp2-hybridisation). Compared to graphite, in non-graphitic carbons the graphenes are also parallely arranged with respect to each other, but show no 3D crystallographic order. Porous non-graphitic carbons have a variety of applications, i.e. purification of gas and water, filters, catalyst supports, electrode material, etc. We develop strategies to characterize such carbons by means of suitable x-ray scattering approaches (small- and wide-angle x-ray scattering) and also methods to prepare such carbons with defined mesoporosity.

Crystallization of nanostructures: Various metal oxides are potentially interesting in nanostrystalline form for diverse applications in the field of energy storage, energy conversion, sensing, etc. However, in most cases only the fully crystalline modification of the respective oxide shows the desired physico-chemical performance. We try to develop sol-gel chemistry routes to prepare well-defined nanostructures (nanoparticles or pores) in highly crystalline form, in particular in the form of thin films. Interestingly, certain oxides, e.g. prepared by dip-coating of dilute solutions, show preferred crystallographic orientation with respect to the substrate (e.g. glas) after annealing, which is usually only observed for single-crystalline substrates.

Mesostructured Films: Nanostructuring of materials will lead to improved physico-chemical properties. In this project, thin, crystalline metal oxide coatings with pores in the range of approx. 5 nm - 30 nm (so-called “mesopores”) are produced using sol-gel chemistry in combination with micellar self-organization. A key goal is to answer the fundamental question of how nanostructuring affects physical properties. For this reason, methods are being developed to achieve high regularity in the arrangement of the mesopores.

Hydrogensulfide threshold sensors: Hydrogensulfide gas (H2S) is an important key gas for the control of biogas plants and must therefore be measured to protect people and machines. For this purpose, threshold sensors for H2S detection based on percolation effects in nanostructured copper oxide materials are to be researched.
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: X-ray and neutron scattering are ideal tools to study nanostructures of a wide variety of materials, for example mesoporous inorganics, liquid-crystals, block copolymer phases, dispersion, etc. We develop and use novel experimental techniques (e.g. in-situ small-angle x-ray and neutron scattering (SAXS/SANS) during sorption of gases in porous hosts). Also our group works on theoretical approaches to analyze scattering data, in particular with respect to account for “disorder”.