By combining measurements of photocatalysis under solar irradiation with measurements
of total organic carbon, we have compared the performance of two TiO2-based photocatalysts in the
photodegradation of the dye Reactive Blue 49 (RB49). TiO2-P25 and TiO2-UV100 commercial photocatalysts
were tested within a concentration ranging from 0.5 to 4 g/L. The dye solution concentration
was varied from 10 to 50 mg/L and its pH was increased from 3 to 9. Extensive characterization of
the photocatalysts was performed using Fourier-transform infrared spectroscopy, scanning electron
microscopy and X-ray diffraction. TiO2-UV100 proved to be more active in adsorbing RB49 dye than
TiO2-P25. At low dye concentrations, the adsorption equilibrium is reached in 15 min. This time
increases to 1 h at higher concentrations. The photocatalytic degradation of aqueous RB49 under
sunlight was monitored by UV-Vis spectrophotometry. The apparent rate constant of dye photodegradation
with TiO2-UV100 is twice that of TiO2-P25. The total organic carbon (TOC) analysis showed a
removal of around 98% with TiO2-UV100 and only 85% with TiO2-P25 after 3 h of solar irradiation.
Over five photocatalytic cycles of 3 h, TiO2-UV100 maintained a more stable and higher efficient
photocatalytic performance. All our results converge toward a better photocatalytic performance of
TiO2-UV100 for the photodegradation of RB49 dye and indicate that the most decisive factor is its
greater capacity to adsorb the pollutant.

Title

Coatings

Publisher

MDPI

Publisher Country

Switzerland

Indexing

Scopus

Impact Factor

1.2

Publication Type

Prtinted only

Volume

14

Year

2024

Pages

1270