Abstract
This study examined the photocatalytic oxidation of gas-phase trichloroethylene (TCE) and 2-propanol, at indoor levels, over titanium dioxide (TiO2) irradiated with light-emitting diodes (LED) under different operational conditions. TiO2 powder baked at 450 °C exhibited the highest photocatalytic decomposition efficiency (PDE) for TCE, while all photocatalysts baked at different temperatures showed similar PDEs for 2-propanol. The average PDEs of TCE over a three hour period were four, four, five, and 51% for TiO2 powders baked at 150, 250, 350, and 450 °C, respectively. The average PDEs of 2-propanol were 95, 97, 98, and 96% for TiO2 powders baked at 150, 250, 350, and 450 °C, respectively. The ratio of anatase at 2θ = 25.2° to rutile at 2θ = 27.4° was lowest for the TiO2 powder baked at 450 °C. Although the LED-irradiated TiO2 system revealed lower PDEs of TCE and 2-propanol when compared to those of the eight watt, black-light lamp-irradiated TiO2 system, the results for the PDEs normalized to the energy consumption were reversed. Other operational parameters, such as relative humidity, input concentrations, flow rate, and feeding type were also found to influence the photocatalytic performance of the UV LED-irradiated TiO2 system when applied to the cleaning of TCE and 2-propanol at indoor air levels.
Highlights
Long-term exposure of building occupants to volatile organic compounds (VOCs) at even low levels has recently been of concern because it is closely associated with adverse health effects [1,2].Many VOC sources such as building materials and consumer products have been identified in residential and industrial buildings [3,4]
The present study examined the effects of baking temperature (BT), light-source type (LST), relative humidity (RH), input concentrations (IC), flow rate (FR), and feeding type (FT)
Was attributed to more transformation of the rutile phase TiO2 at this BT. This assertion is supported by the X-ray diffraction (XRD) results of the TiO2 powders baked at the four different temperatures (Figure 2)
Summary
Long-term exposure of building occupants to volatile organic compounds (VOCs) at even low levels has recently been of concern because it is closely associated with adverse health effects [1,2]. LEDs are more efficient at converting electricity into light due to high quantum yields close to unity that lead to low electricity consumption They have a long life, with a typical lifetime of 25,000 to 100,000 h [14]. LEDs provide a tunable, almost monochromatic light These characteristics have prompted the application of LEDs to the photocatalytic decomposition of environmental pollutants instead of conventional lamps. The current study investigated the photocatalytic oxidation of gaseous TCE and 2-propanol, at indoor levels, over TiO2 irradiated with LEDs using an annular-type plug-flow reactor. These target compounds were selected based on their prevalence in indoor environments [5]. The present study examined the effects of baking temperature (BT), light-source type (LST), relative humidity (RH), input concentrations (IC), flow rate (FR), and feeding type (FT)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
