Exploring the Photothermo-Catalytic Performance of Brookite TiO2-CeO2 Composites

Abstract

<jats:p>The thermocatalytic, photocatalytic and photothermo-catalytic oxidation of some volatile organic compounds (VOCs), 2-propanol, ethanol and toluene, was investigated over brookite TiO2-CeO2 composites. The multi-catalytic approach based on the synergistic effect between solar photocatalysis and thermocatalysis led to the considerable decrease in the conversion temperatures of the organic compounds. In particular, in the photothermo-catalytic runs, for the most active samples (TiO2-3 wt% CeO2 and TiO2-5 wt% CeO2), the temperature at which 90% of VOC conversion occurred was about 60 °C, 40 °C and 20 °C lower than in the thermocatalytic tests for 2-propanol, ethanol and toluene, respectively. Furthermore, the addition of cerium oxide to brookite TiO2 favored the total oxidation to CO2 already in the photocatalytic tests at room temperature. The presence of small amounts of cerium oxide allowed to obtain efficient brookite-based composites facilitating the space charge separation and increasing the lifetime of the photogenerated holes and electrons as confirmed by the characterization measurements. The possibility to concurrently utilize the photocatalytic properties of brookite and the redox properties of CeO2, both activated in the photothermal tests, is an attractive approach easily applicable to purify air from VOCs.</jats:p>

Oxide-based composites: applications in thermo-photocatalysis

“…The thermo-photo activity of CeO2 has been studied together other oxides 109,113,114 . TiO2/CeO2 was synthesized by Zeng et al and utilized for the gas-phase oxidation of benzene 109 .…”

Biotemplate Assisted Nano Titania and Its Environmental Performance

“…Hence it is mandatory to monitor and confirm the standard of the same by regular evaluation of their physical, chemical and biological parameters through water treatment processes prior to their discharge. In this regard heterogeneous photocatalysis using semiconductor metal oxides as catalysts proved to be highly dominating among different water treatment techniques in removing pollutants from water and air without leaving any secondary pollutants [7].…”

Editorial Catalysts: Special Issue on Recent Advances in TiO2 Photocatalysts

“…However, due to the large energy band gap, its activity in the range of natural solar light is quite limited. For this reason, the development of new TiO 2 -based photocatalysts active in the visible range has become a new research trend [1,3,6,13,[15][16][17][18][19]. The effectivity can also be improved by modifying TiO 2 with noble metals [2,13,15] or by Ti 3+ -self-doped TiO 2 modification [11].…”

“…Bettoni and co-workers demonstrated the experimental and theoretical investigation on the TiO 2 catalytic elimination of methane, hexane, isooctane, acetone, and methanol, following the microscopic mechanism based on the Langmuir-Hinshelwood approach [24]. Bellardita et al investigated the degradation of 2-propanol, ethanol, and toluene under visible light in the presence of brookite TiO 2 -CeO 2 composites in their study [19]. It was found that the addition of cerium oxide to brookite TiO 2 favored the total oxidation to CO 2 .…”

“…It was found that the addition of cerium oxide to brookite TiO 2 favored the total oxidation to CO 2 . Moreover, the combination of thermocatalysis and photocatalysis mechanisms was considered [19]. The effect of QDs-sensitized TiO 2 composite types (AgInS 2 , SnS, CuS 2 , Bi 2 S 3 ) on the decomposition of toluene was investigated by Malankowska and coworkers [25].…”