Investigating the existence of a stable TiO2 mesophase for use in electrocatalysis

The photo-electrocatalytic reduction of CO2 (CO2R) to CO, CH4, CH3OOH and other short chain alcohols holds great promise as these reaction products have high industrial-value. But achieving selectivity for a desired product with high efficiencies remains a challenge. The current efforts in our lab are directed towards developing a fundamental understanding of the semiconductor | solution interface, by using a TiO2 thin film model system, to see if semiconductor electrodes may offer a solution.  

These TiO2 electrodes may be produced by varying techniques and under varying conditions to give different phases. But most still seem to exhibit a certain “activation” behavior. This activation is often also intentionally achieved to produce lesser understood ‘reduced titania’, or ‘black titania’ phases for employment in catalysis. During the thesis, the student will perform a systematic study of different TiO2 phases for its activation to investigate the existence of a stable “mesophase”. Techniques like ALD, sputtering and anodization will be employed for preparation of dense or porous TiO2 thin film electrodes. Electrochemical studies on these electrodes will be done in aqueous and non-aqueous solutions using different electrolytes and redox probes, taking inspiration from battery literature. Characterization techniques like XRD, SEM, ERD, Raman and impedance spectroscopies will also be utilized. By closely working with colleagues at the Energy Storage and Conversion team at imec, the student will have a great opportunity to build a solid foundation in electrochemistry. You may send your queries at divyansh.khurana@imec.be.