TiO2 sol-gel for formaldehyde photodegradation using polymeric support: photocatalysis efficiency versus material stability

Abstract

Photocatalysts supported on polymers are not frequently used in heterogeneous photocatalysis because of problems such as wettability and stability that affect photocatalysis conditions. In this work, we used polypropylene as support for TiO2 sol-gel to evaluate its stability and efficiency under UV radiation. We also tested the effect of the thermo-pressing PP/TiO2 system on the photocatalytic efficiency and stability under UV radiation. The films were characterized by scanning electron microscopy (SEM), UV-Vis spectroscopy and X-ray diffraction (XRD). The SEM micrographs showed that the films of TiO2 sol-gel onto PP has approximately 1.0-μm thick and regular surface and the generation of polypropylene nanowires on hot-pressed samples. XRD showed the formation of TiO2 anatase on the surface of the films made by dip-coating. All photocatalysts were tested in decontaminating air-containing gaseous formaldehyde (70 ppmv) presenting degradation of the target compound to the limit of detection. The photocatalysts showed no deactivation during the entire period tested (30 h), and its reuse after washing showed better photocatalytic performance than on first use. The photocatalyst showed the best results were tested for 360 h with no observed deactivation. Aging studies showed that the film of TiO2 causes different effects on the photostability of composites, with stabilizing effect when exposed to most energetic UVC radiation (λmax = 254 nm) and degradative effects when exposed to UVA radiation (λmax = 365 nm).

Photocatalytic VOCs Degradation Efficiency of Polypropylene Membranes by Incorporation of TiO2 Nanoparticles

“…An advantage of using polymeric materials is that they are less expensive as raw materials than metals and also less expensive to manufacture into finished products than glass and metals. It is to be noted that TiO 2 can be used to eliminate contaminants by coating with various polymers [ 18 ].…”

Innovative and stable TiO 2 supported catalytic surfaces removing aldehydes under UV-light irradiation

“…Photocatalytic TiO 2 materials have been widely used during the last four decades due to their low cost, photo-activity and stability [5]. TiO 2 is widely used in catalytic processes occurring at the air-solid interface at room temperature and atmospheric pressure [6][7][8]. TiO 2 (titania) stands out as one of the most active photocatalyst [9] under UV-radiation.…”

Evaluation of absorption efficiency of Zeolite ZSM-5 in the removal of styrene vapors

“…Moreover, the results of SEM showed that synthesized zeolite particles had an equal size which can increase the efficiency of zeolite in the styrene removal process. Wen Liang et al used XRD to characterize nanoparticles (23). Taking into consideration the peaks in XRD curve, they determined the purity of titanium dioxide nanoparticles used in their study.…”

“…The analysis also showed that an increase in the concentration of styrene gas flow reduced the time of reaching saturation and the cutoff point. With increasing the concentration of the absorbing element, the speed of the absorption process increases which is due to the presence of a large number of gas molecules of the absorbing element that increases their transfer and contact with the adsorbent surface (23,24). As a result, by increasing the concentration of styrene gas at a constant flow rate, zeolite could reach the cutoff point earlier.…”