The use of small volume TOC analysis as complementary, indispensable tool in the evaluation of photocatalysts at lab-scale
Faculty of Sciences. Chemistry
Faculty of Pharmaceutical, Biomedical and Veterinary Sciences. Pharmacy
Studies in surface science and catalysis. - Amsterdam
, p. 321-324
University of Antwerp
Total Organic Carbon-analysis (TOC) on micro volume (μV) liquids was applied for the first time by means of a special designed Shimadzu gas injection kit®. This way, it became possible to evaluate the efficiency of photocatalytic dye degradation in terms of CO2 conversion (photomineralization) simultaneously with classic UV-Vis (photobleaching) measurements within a small, lab-scale photocatalytic test setup. The possibility to allow multiple micro volume sampling in short time intervals during several hours without a substantial decrease in volume/catalyst ratio is of particular value in the evaluation of photocatalysts on lab-scale volumes (< 100 ml). By combining both complementary techniques (UV-Vis and μV TOC), indispensable, additional knowledge on the degradation process/mechanism and the catalyst efficiency can be obtained in a fast, inexpensive and easy way. In this study, the photocatalytic acitivity of mesoporous titania (EISA TNH4OH C450) and hydrogen trititanate nanotubes (H-TNT) towards the degradation of rhodamine 6G was investigated. It has been illustrated that the detailed TOC-plots add important, complementary information to the data obtained by UV-Vis analysis that can reveal rate limiting steps, surface adsorption effects and charge effects. This can lead to a better evaluation of the catalyst and improved insights in the various degradation mechanisms that can occur.