Details
| Original language | English |
|---|---|
| Article number | 114749 |
| Journal | Catalysis today |
| Volume | 437 |
| Early online date | 29 Apr 2024 |
| Publication status | Published - 1 Jul 2024 |
| Externally published | Yes |
Abstract
Photocatalysis holds promise for the removal of NOx from the air, yet its limited selectivity toward desired products (e.g. nitrate ions) hinders its widespread application. In this study, we synthesized and comprehensively characterized amorphous TiO2 microspheres (ATMS), fluoride-etched TMS (F-TMS), and Al2O3-modified F-TMS (Al2O3/F-TMS) photocatalysts. The photocatalytic NOx abatement tests revealed negligible photoactivity for the TMS, with significant improvement observed after the fluoride ions etching using the hydrothermal method. However, the selectivity of F-TMS for NOx removal remained lower than that of TiO2 P25. The Al2O3/F-TMS photocatalyst exhibited a substantial increase in selectivity. The analysis of NOx abatement results indicated a 2.7-fold boost in selectivity compared to TiO2 P25. A reasonable correlation between the amount of chemically absorbed water and nitrate selectivity was observed. The electron paramagnetic resonance (EPR) disclosed that the fluoride etching induced the formation of intra-band-gap hole-trapping sites and thus enhanced the photocatalytic activity. Nevertheless, the selectivity improvement was mainly attributed to Al2O3's ability to stabilize the NOx oxidation intermediates at the surface for subsequent oxidation to nitrate ions. This study provides valuable insights for tailoring photocatalysts to enhance both activity and selectivity in photocatalytic NOx abatement.
Keywords
- EPR analysis, Hole trapping sites, Photocatalysis, Nitrate selectivity, NO abatement, TiO microspheres
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis
- Chemistry(all)
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In: Catalysis today, Vol. 437, 114749, 01.07.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Fluoride-etched TiO2 microspheres modified with Al2O3 for enhanced photocatalytic conversion of NOx into nitrate ions
AU - Kandiel, Tarek A.
AU - Kamran, Muhammad
AU - Morsy, Mohamed A.
AU - Bahnemann, Detlef W.
AU - Ahmed, Amira Y.
N1 - Publisher Copyright: © 2024 Elsevier B.V.
PY - 2024/7/1
Y1 - 2024/7/1
N2 - Photocatalysis holds promise for the removal of NOx from the air, yet its limited selectivity toward desired products (e.g. nitrate ions) hinders its widespread application. In this study, we synthesized and comprehensively characterized amorphous TiO2 microspheres (ATMS), fluoride-etched TMS (F-TMS), and Al2O3-modified F-TMS (Al2O3/F-TMS) photocatalysts. The photocatalytic NOx abatement tests revealed negligible photoactivity for the TMS, with significant improvement observed after the fluoride ions etching using the hydrothermal method. However, the selectivity of F-TMS for NOx removal remained lower than that of TiO2 P25. The Al2O3/F-TMS photocatalyst exhibited a substantial increase in selectivity. The analysis of NOx abatement results indicated a 2.7-fold boost in selectivity compared to TiO2 P25. A reasonable correlation between the amount of chemically absorbed water and nitrate selectivity was observed. The electron paramagnetic resonance (EPR) disclosed that the fluoride etching induced the formation of intra-band-gap hole-trapping sites and thus enhanced the photocatalytic activity. Nevertheless, the selectivity improvement was mainly attributed to Al2O3's ability to stabilize the NOx oxidation intermediates at the surface for subsequent oxidation to nitrate ions. This study provides valuable insights for tailoring photocatalysts to enhance both activity and selectivity in photocatalytic NOx abatement.
AB - Photocatalysis holds promise for the removal of NOx from the air, yet its limited selectivity toward desired products (e.g. nitrate ions) hinders its widespread application. In this study, we synthesized and comprehensively characterized amorphous TiO2 microspheres (ATMS), fluoride-etched TMS (F-TMS), and Al2O3-modified F-TMS (Al2O3/F-TMS) photocatalysts. The photocatalytic NOx abatement tests revealed negligible photoactivity for the TMS, with significant improvement observed after the fluoride ions etching using the hydrothermal method. However, the selectivity of F-TMS for NOx removal remained lower than that of TiO2 P25. The Al2O3/F-TMS photocatalyst exhibited a substantial increase in selectivity. The analysis of NOx abatement results indicated a 2.7-fold boost in selectivity compared to TiO2 P25. A reasonable correlation between the amount of chemically absorbed water and nitrate selectivity was observed. The electron paramagnetic resonance (EPR) disclosed that the fluoride etching induced the formation of intra-band-gap hole-trapping sites and thus enhanced the photocatalytic activity. Nevertheless, the selectivity improvement was mainly attributed to Al2O3's ability to stabilize the NOx oxidation intermediates at the surface for subsequent oxidation to nitrate ions. This study provides valuable insights for tailoring photocatalysts to enhance both activity and selectivity in photocatalytic NOx abatement.
KW - EPR analysis
KW - Hole trapping sites, Photocatalysis
KW - Nitrate selectivity
KW - NO abatement, TiO microspheres
UR - http://www.scopus.com/inward/record.url?scp=85192099082&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2024.114749
DO - 10.1016/j.cattod.2024.114749
M3 - Article
AN - SCOPUS:85192099082
VL - 437
JO - Catalysis today
JF - Catalysis today
SN - 0920-5861
M1 - 114749
ER -