Size-Dependent Photocatalytic Activity of Silver Nanoparticles Embedded in ZX-Bi Zeolite Supports

Houeida Issa Hamoud (1) , Fatima Douma (1, 2) , Mama Lafjah (2) , Fatiha Djafri (2) , Oleg Lebedev (3, 4) , Valentin Valtchev (1) , Mohamad El-Roz (1)

1 LCS - Laboratoire catalyse et spectrochimie
2 Université d'Oran 1 Ahmed Ben Bella [Oran]
3 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
4 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

In this study, the photocatalytic activity of highly dispersed silver embedded into ZX-Bi zeolite during methanol photooxidation under visible light and at room temperature is investigated. The size and dispersion of Agn δ+ sub-nanoclusters (< 1 nm) is studied by HR/TEM, DR-UV-Vis, in situ FTIR, etc. The catalytic tests were performed using the operando FTIR technique during methanol photooxidation as a model reaction. The results show that the as-prepared Ag/ZX-Bi was very low active, while the activated sample at 200 °C (Ag/ZX-Bi_200) exhibits the highest photocatalytic activity (49.60 mmol.g-1 .cm-2 after 12 h of reaction) during methanol photooxidation, more than 6 times higher than the TiO2-P25 used as reference. This activity originates from the migration and agglomeration of sub-nanosized Agn d+ clusters into Ag nanoparticles with a size of 6 nm. However, the catalyst experienced a partial desactivation when the particle size of sintered Ag NPs is below 20 nm. The activity and the deactivation of Ag/ZX-Bi will be discussed on the basis of operando FTIR results and HRTEM analysis at different stages of the reaction.

Mots clés: size effect; plasmonic catalyst; photocatalysis; operando; Silver nanoparticles; size effect

Domaines: Catalyse

Houeida Issa Hamoud, Fatima Douma, Mama Lafjah, Fatiha Djafri, Oleg Lebedev, et al.. Size-Dependent Photocatalytic Activity of Silver Nanoparticles Embedded in ZX-Bi Zeolite Supports. ACS Applied Nano Materials, In press, 5 (3), pp.3866-3877. ⟨10.1021/acsanm.1c04484⟩. ⟨hal-03595630⟩