TY - JOUR
T1 - CdTe Quantum Dot-Functionalized P25 Titania Composite with Enhanced Photocatalytic NO2 Storage Selectivity under UV and Vis Irradiation
AU - Balci Leinen, Merve
AU - Dede, Didem
AU - Khan, Munir Ullah
AU - Caglayan, Mustafa
AU - Koçak, Yusuf
AU - Demir, Hilmi Volkan
AU - Ozensoy, Emrah
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: E.O. acknowledges the scientific collaboration with TARLA project founded by the Ministry of Development of Turkey (project code: DPT2006K-120470). H.V.D. is grateful to the support from TUBA. The authors acknowledge SASOL Ltd. for providing Puralox SBA200 γ-Al2O3 materials.
PY - 2018/12/11
Y1 - 2018/12/11
N2 - Composite systems of P25 (titania) functionalized with thioglycolic acid (TGA)-capped CdTe colloidal quantum dots (QDs) were synthesized, structurally characterized, and photocatalytically tested in the photocatalytic NO oxidation and storage during NO(g) + O(g) reaction. Pure P25 yielded moderate-to-high NO conversion (31% in UV-A and 40% in visible (vis)) but exhibited extremely poor selectivity toward NO storage in solid state (25% in UV-A and 35% in vis). Therefore, P25 could efficiently photooxidize NO(g) + O(g) into NO; however, it failed to store photogenerated NO and released toxic NO(g) to the atmosphere. CdTe QD-functionalized P25 revealed a major boost in photocatalytic performance with respect to pure P25, where NO conversion reached 42% under UV-A and 43% under vis illumination, while the respective selectivity climbed up to 92 and 97%, rendering the CdTe/P25 composite system an efficient broad-band photocatalyst, which can harvest both UV-A and vis light efficiently and display a strong NO abatement effect. Control experiments suggested that photocatalytic active sites responsible for the NO(g) + O(g) photooxidation and formation of NO reside mostly on titania, while the main functions of the TGA capping agent and the CdTe QDs are associated with the photocatalytic conversion of the generated NO to the adsorbed NO species, significantly boosting the selectivity toward solid-state NO storage. Reuse experiments showed that photocatalytic performance of the CdTe/P25 system can be preserved to a reasonable extent with only a moderate decrease in the photocatalytic performance. Although some decrease in the photocatalytic activity was observed after aging, CdTe/P25 could still outperform P25 benchmark photocatalyst. Increasing CdTe QDs loading from the currently optimized minuscule concentrations could be a useful strategy to increase further the catalytic lifetime/stability of the CdTe/P25 system with only a minor penalty in catalytic activity.
AB - Composite systems of P25 (titania) functionalized with thioglycolic acid (TGA)-capped CdTe colloidal quantum dots (QDs) were synthesized, structurally characterized, and photocatalytically tested in the photocatalytic NO oxidation and storage during NO(g) + O(g) reaction. Pure P25 yielded moderate-to-high NO conversion (31% in UV-A and 40% in visible (vis)) but exhibited extremely poor selectivity toward NO storage in solid state (25% in UV-A and 35% in vis). Therefore, P25 could efficiently photooxidize NO(g) + O(g) into NO; however, it failed to store photogenerated NO and released toxic NO(g) to the atmosphere. CdTe QD-functionalized P25 revealed a major boost in photocatalytic performance with respect to pure P25, where NO conversion reached 42% under UV-A and 43% under vis illumination, while the respective selectivity climbed up to 92 and 97%, rendering the CdTe/P25 composite system an efficient broad-band photocatalyst, which can harvest both UV-A and vis light efficiently and display a strong NO abatement effect. Control experiments suggested that photocatalytic active sites responsible for the NO(g) + O(g) photooxidation and formation of NO reside mostly on titania, while the main functions of the TGA capping agent and the CdTe QDs are associated with the photocatalytic conversion of the generated NO to the adsorbed NO species, significantly boosting the selectivity toward solid-state NO storage. Reuse experiments showed that photocatalytic performance of the CdTe/P25 system can be preserved to a reasonable extent with only a moderate decrease in the photocatalytic performance. Although some decrease in the photocatalytic activity was observed after aging, CdTe/P25 could still outperform P25 benchmark photocatalyst. Increasing CdTe QDs loading from the currently optimized minuscule concentrations could be a useful strategy to increase further the catalytic lifetime/stability of the CdTe/P25 system with only a minor penalty in catalytic activity.
UR - http://hdl.handle.net/10754/631587
UR - https://pubs.acs.org/doi/10.1021/acsami.8b18036
UR - http://www.scopus.com/inward/record.url?scp=85059425564&partnerID=8YFLogxK
U2 - 10.1021/acsami.8b18036
DO - 10.1021/acsami.8b18036
M3 - Article
SN - 1944-8244
VL - 11
SP - 865
EP - 879
JO - ACS Applied Materials & Interfaces
JF - ACS Applied Materials & Interfaces
IS - 1
ER -