Photocatalytic oxidation of selected gas-phase VOCs using UV light, TiO2, and TiO2/Pd

Abstract

Heterogeneous photocatalytic oxidation systems using titanium dioxide (TiO) have been extensively studied for the removal of several volatile organic compounds (VOCs). The addition of noble metals such as palladium on TiO may improve photocatalytic activity by increasing charge separation efficiency. In this work, palladium was impregnated on TiO and the efficiency of the new catalyst was tested and compared with that of pure TiO. Pd was impregnated on TiO by the reduction method, using NaBH, and was characterized by XRD, XPS, UV-Vis, and H chemisorption. The photocatalytic tests were performed in an annular coated-wall reactor using octane, isooctane, n-hexane, and cyclohexane at inlet concentrations varying from 100 to 120 ppmv. Compared with pure TiO film, the photocatalytic activity of TiO impregnated with 1 wt% of palladium was improved. All the aforementioned analytical techniques confirmed the presence of Pd incorporated into the structure of TiO and the conversion rates were studied in a broad range of residence times, yielding up to 90 % or higher rates in 40 s of residence time, thus underscoring the relevant contribution of the technology.

Enhanced Photocatalytic Activity and Stability of Bi2WO6 – TiO2-N Nanocomposites in the Oxidation of Volatile Pollutants

“…The potentials of photogenerated electrons and holes are high enough for the formation of reactive oxygen species, which can provide oxidative degradation of various types of pollutants [ 5 , 6 ]. The degradation of aromatics, ketones, aldehydes, alcohols, carboxylic acids, alkanes, alkenes, and heterocompounds was investigated and discussed in the previously published papers [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. However, a wide band gap of TiO 2 (3.0–3.2 eV) does not allow for efficient utilization of sunlight because TiO 2 can absorb radiation with wavelengths shorter than 400 nm (i.e., UV light) that corresponds to less 5% of the total solar light [ 15 ].…”

Self-cleaning and air de-pollution performance of TiO2/SiO2 and N-TiO2/SiO2 photocatalysts coated on Portland cement mortar substates

“…the UV region of sunlight (Pelaez et al 2012). Great efforts have been made to increase the absorption of TiO 2 in the visible range and reduce the recombination of the photogenerated electron/hole pairs, like loading of noble metal (Au, Pd, and Pt) (Fujimoto et al 2017; Torras-Rosell et al 2017; Yu et al 2021). Although noble metals have been extensively used and recognised as good cocatalysts for improving the photocatalytic activity of titanium dioxide, these cocatalysts are scarce metals that are expensive to use; therefore, are not the appropriate choice for large-application, as in the case of building materials.…”

C-dot doping for enhanced catalytic performance of TiO2/5A for toluene degradation in non-thermal plasma-catalyst system

“…Some transition metal oxides such as ZnO, MnO 2 , NiO, CoO, WO 3 , and TiO 2 (Li et al 2020a;Vandenbroucke et al 2011) have been used as catalysts in combination with NTP to improve the removal of VOCs and mineralization efficiency (Kim et al 2008). Heterogeneous photocatalytic oxidation systems using TiO 2 have been extensively studied for the removal of environmental pollution compounds (Fujimoto et al 2017). Due to its high photocatalytic activity, high stability, nontoxicity, and cost-effectiveness (Shayegan et al 2018), TiO 2 has become a promising photocatalysis material for water purification and remediation of air pollution (Ghosh et al 2016;Verbruggen 2015).…”