open access

https://hdl.handle.net/2115/90096

The property-governed activity of silver-modified titania photocatalysts : The influence of titania matrix

英語

2022-06-28

AIP Publishing

Journal of chemical physics

156(24)

244706

Commercial titania photocatalysts were modified with silver nanoparticles (NPs) by the photodeposition method in the presence/absence of methanol. The obtained photocatalysts were characterized by XRD, XPS, diffuse reflectance spectroscopy, STEM, and time-resolved microwave conductivity (TRMC) methods. The photocatalytic activity was tested under UV/vis irradiation for (i) methanol dehydrogenation (during silver deposition), (ii) oxygen evolution with in situ silver deposition, and (iii) oxidative decomposition of acetic acid, as well as under vis irradiation for 2-propanol oxidation. The action spectra of 2-propanol oxidation were also performed. It has been confirmed that modification of titania with silver causes significant improvement of photocatalytic activity under both UV and vis irradiation as silver works as an electron scavenger (TRMC data) and vis activator (possibly by an energy transfer mechanism). The obtained activities differ between titania samples significantly, suggesting that the type of crystalline phase, particle/crystallite sizes, and electron traps' density are crucial for both the properties of formed silver deposits and resultant photocatalytic activity. It might be concluded that, under UV irradiation, (i) high crystallinity and large specific surface area are recommended for rutile- and anatase-rich samples, respectively, during hydrogen evolution, (ii) mixed crystalline phases cause a high rate of oxygen evolution from water, and (iii) anatase phase with fine silver NPs results in efficient decomposition of acetic acid, whereas under vis irradiation the aggregated silver NPs (broad localized surface plasmon resonance peak) on the rutile phase are promising for oxidation reactions. Published under an exclusive license by AIP Publishing.

学術雑誌論文

Accepted Manuscript

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Kenta Yoshiiri, Baris Karabiyik, Kunlei Wang, Zhishun Wei, Christophe Colbeau-Justin, and Ewa Kowalska , "The property-governed activity of silver-modified titania photocatalysts: The influence of titania matrix", J. Chem. Phys. 156, 244706 (2022) https://doi.org/10.1063/5.0097762 and may be found at https://doi.org/10.1063/5.0097762

0021-9606