Photocatalytic Properties of Commercially Available TiO2: Study of Fotosan® and InterBrasil® FA-101 for H2S Degradation Using UV and Solar Radiation

This paper proposes the study and comparison of two commercial photocatalysts of TiO₂ when applied as coating on a fibrocement roof tile. Are reported their respective photocatalytic activities, chemical, morphological, and textural characteristics. For that, commercial photocatalysts InterBrasil® FA-101 and Fotosan® were deposited on fibrocement support to perform photocatalytic activity tests and characterization analyses. The measurement of the photocatalytic activity of each sample was carried out through the efficiency of H₂S degradation, using artificial (UV lamp) and natural (solar lighting) radiation. The surfaces formed with this photocatalyst coating were characterized by scanning electron microscopy, with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, diffuse reflectance spectroscopy (DRS), and Fourier infrared transformation using attenuated total reflection (ATR-FTIR). The volumetric flow rate and saturation time (deactivation) were evaluated as operational performance parameters of the degradation reaction. The X-ray diffraction shows that TiO₂ formed in the coatings correspond to the anatase phase. In addition, the pore volume of the coatings was from 4.9 to 9.0 × 10⁻³ g cm⁻³ and the superficial area was from 19.6 to 30.5 m² g⁻¹ that is considered relatively high. The results showed that, unlike the Fotosan®, the type of radiation used had a greater influence on the InterBrasil® FA-101, since there was a reduction of the photocatalytic activity when the solar radiation was used. The H₂S degradation efficiency of 80% was obtained for a residence time (RT) of 115 s using Fotosan®, whereas that for InterBrasil® FA-101 was reached 45% for the same RT. Lower on the photocatalytic activity was observed after 30 min and 390 min of reaction for the InterBrasil® FA-101 and Fotosan®, respectively. The sample containing Fotosan® was the most effective photocatalyst in comparison with InterBrasil® FA-101.