Topics for Bachelor Theses, Laboratory Courses and Master Theses

Systematic investigations of structural components in CeO2/B2O3/Na2O glass

Topics for Bachelor Theses and Laboratory Courses (M. Sc. Felix Meyerhöfer):

On the way to new glass materials with catalytic activity, there are many possible elements and combinations of thereof. Not all catalytically active materials can be processed into glass and not all glass-forming elements have interesting catalytic properties.
For the lanthanoid cerium oxide, however, these two properties meet.
Cerium oxide can already be found in automotive catalytic converters today. Cerium oxide has the ability to oxidize carbon monoxide to carbon dioxide under oxygen deficiency in the exhaust gas stream and to reactivate itself afterwards in case of excess oxygen in the exhaust gas. These and other applications, such as a potential use in hydrogen production using solar energy, make cerium oxide an interesting compound with direct relevance to everyday life. As a glass with an amorphous structure, this offers new possibilities for shaping and modification.
However, it is first necessary to understand the basic structure and the interaction of the material system.

  • Melting of glasses in the system CeO2/B2O3/Na2O with fixed B to Na ratio and variable ratio CeO2 to B2O3. Subsequent structural investigations by means of DTA/TG, dilatometry, Raman, XPS, REM.
  • Investigation of temperature induced phase separation in the CeO2/B2O3/Na2O system and subsequent extraction of the alkali-rich borate phase to produce porous CeO2 glass. Subsequent characterization by means of N2 low temperature adsoprion, Hg porosimetry, SEM.

Synthesis of visible light active porous TiO2 contaning glasses for photocatalytic applications

Topics for  Laboratory Courses (M. Sc. Tovhowani Kwinda):

TiO2 exhbit larger band gap (3.2 eV), thus, the absorption onset falls in the UV region resulting in low efficiency for visible or sunlight driven photocatalytic applications. The UV fraction of the sunlight reaching the earth surface is only 4 % whereas the visible fraction reaches approximatly 50%. Therefore, developing materials which can effectively harness visible part of the solar spectrum would represent remarkable breakthrough towards large scale application of photocatalysis (e.g., in water remediation, air purification, etc). In this work, porous TiO2 containing glasses/ceramics will be prepared with some additional transition metal oxide additives for direct applications in water remediation. Since glasses/ceramics can be prepared in various geometric shapes, this will also eliminate the usage of TiO2 nanopowders due to the extensive catalyst recovery step.

last modified: 03.09.2020