Graphitic carbon nitride thin films for light-induced photocatalysis in a slit geometry microreactor

0562924 - ÚCHP 2023 RIV GB eng J - Journal Article
Dolai, Susmita - Vanluchene, Anna - Stavárek, Petr - Dzik, P. - Fajgar, Radek - Soukup, Karel - Klusoň, Petr
Graphitic carbon nitride thin films for light-induced photocatalysis in a slit geometry microreactor.
Journal of Environmental Chemical Engineering. Roč. 10, č. 6 (2022), č. článku 108790. ISSN 2213-2929. E-ISSN 2213-3437
R&D Projects: GA TA ČR(CZ) SS02030008
Institutional support: RVO:67985858
Keywords : photochemistry * photo-microreactor * carbon nitride
OECD category: Chemical process engineering
Impact factor: 7.7, year: 2022
Method of publishing: Open access with time embargo

A combination of a photocatalysis and a micro-flow technology provides a highly capable tool for the design and utilisation of functional thin films. Here, they are represented by graphitic carbon nitride films, potentially used for photo-oxidations in environmental chemistry or for hydrogen evolution by water splitting. The optimised synthesis involves a study of the role of monomers, solvents, calcination temperatures, particle size, etc., in respect of the achieved photocatalytic activity. Films were prepared from the mixture of milled powder catalysts and a binder, dried, and subjected to post-processing treatments (post annealing, plasma application). The intended functionality was assessed in two types of reactions, photo-oxidation of a fluorescent dye, Rhodamine B,
and photo-oxidation of a common antibiotic, Tetracycline. The performance was compared for the bulk catalyst, and for the thin film. In either case, the same part of light spectrum, concentrations, and other conditions were applied. However, for the thin films, a special experimental setup was utilised. It had the appearance of a micro flow apparatus designed as a slit geometry photo-microreactor. Comparison of the two different reaction systems revealed the advantages of the thin film catalyst, which was immobilised directly on the photo-microreactor wall. The specific rate constant was more than 50 times higher in this arrangement for both model reactants. In addition, thin films of g-C3N4 were stable and well adherent during the microreactor tests with the repetitive
reaction cycles. Plasma treatment considerably increased the hydrophilicity of the dried thin films, which resulted in their substantially higher photoactivity.
Permanent Link: https://hdl.handle.net/11104/0335083