Photocatalytic Oxidation of PCE and Butyraldehyde over Titania Modified with Perovskite Optical Crystal BaTiO₃

Abstract

Photocatalysis utilizes near-UV or visible light to break down organic pollutants into innocuous compounds at room temperatures. This paper introduces the use of semiconducting optical crystals as an additive to a photocatalyst. The perovskite optical material BaTiO 3 (band gap of 3.7-3.8 eV) is found to increase VOC destruction when black light is used. The best composition found is 0.1 wt % BaTiO 3 with the balance being TiO 2 . This photocatalyst increases tetrachloroethylene (PCE) conversion by 12 % to 32 % for space times between 1.4 and 17.2 seconds and inlet concentrations of 40 to 130 ppm with a 4 W black light. The average enhancement is approximately 25 %. For butyraldehyde conversion the maximum enhancement is 20 % at 130 ppm in 3.6 seconds. The UV/VIS spectroscopy data indicate a lower absorbance with the additive. The reaction parameters studied are space velocity, inlet concentration and light source. Oxidation by-products are identified using a GCMS.

Synthesis and study of physicochemical, sorption, and photocatalytic properties of barium titanate-modified titania powder

“…The increase in k d for these modified materials in comparison with pure titanium dioxide and barium titanate is associated both with increasing specific sur face area (Table 1) and, apparently, with the appear ance of heterojunctions between the phases, which cause charge separation by UV irradiation and increase the lifetime of charge carriers, impeding charge recombination [17]. Moreover, barium titanate has a high dielectric constant (20-25 at 10 kHz), whereby the charge separation can be maintained for a long time [17,18].…”

“…Moreover, barium titanate has a high dielectric constant (20-25 at 10 kHz), whereby the charge separation can be maintained for a long time [17,18].…”

Facile Method To Prepare TiO2 Hollow Fiber Materials via Replication of Cotton Fiber

“…Photocatalysis utilizes near-UV or visible light to break down organic pollutants into innocuous compounds at room temperature. 17 In general, TiO 2 is only photoexcited by UV light due to its wide band gap. Various attempts have been made to overcome this problem in order to improve the photocatalytic activity under visible light, such as metal ion doping, 18 polymer complex, 19 surface chemical modification, 20 and dye sensitization.…”

“…Photocatalysis utilizes near-UV or visible light to break down organic pollutants into innocuous compounds at room temperature . In general, TiO 2 is only photoexcited by UV light due to its wide band gap.…”

Optical Properties and Photocatalytic Activity of Marokite-Type CaMn 2 O 4

“…The results indicate that the excitation of the charge carriers plays a primary role in controlling the photocatalysis. [9,10] Recently, manganese-based oxides with spinel-or perovskite-type structures have been extensively investigated due to their unique phenomena under light irradiation, i.e., photo-induced magnetization (PIM), photo-induced phase transition (PIPT) and photoinduced charge transfers (PICT). [3,11,12] These phenomena are closely related to the electronic structure under certain conditions, such as the element doping effect, [13] temperature effect [14] and, especially, the photo-excited effect.…”