Naslov
Photocatalytic activity of thin ZnO ALD films deposited on porous substrates

Autori
Kavre Piltaver, Ivna ; Jelovica Badovinac, Ivana ; Veličan, Karlo ; Omerzu, Aleš

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
4th CROATIAN MICROSCOPY CONGRESS with international participation: Book of Abstracts / - , 2022, 95-95

ISBN
978-953-7941-41-3

Skup
4th Croatian Microscopy Congress (CMC 2022)

Mjesto i datum
Poreč, Hrvatska, 18.05.2022. - 20.05.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
fotokatalitička aktivnost, poroznost, pretražni elektronski mikroskop
(zinc oxide, thin films, photocatalytic activity, porosity, scanning electron microscopy)

Sažetak
Zinc oxide (ZnO) is a wide bandgap semiconducting material with a wide range of applications, including UV light emitters, solar cells, gas sensors, piezoelectricity, environmental engineering and photocatalysis. Recently, ZnO thin films have attracted much attention due to their unique advantages such as high photocatalytic ability, transparency and reusability. Atomic layer deposition (ALD) represents an excellent technique for the synthesis of ZnO thin films because it allows precise control of the film thickness, is easy to handle, exhibits high conformality of the obtained films and enables reproducible growth of defect-free films. In recent years, it has been shown that photocatalytic ZnO films grown on flat solid substrates or nanoparticles can be used in water purification systems [1-3]. On the one hand, powders or colloidal suspensions of nanoparticles are particularly efficient systems because they have a high surface-to-volume ratio, which increases the number of available surface states serving as reaction sites. Moreover, the nanoparticles are easily mixed with the contaminated solution. However, their subsequent separation from the solution is a challenging and expensive process. Therefore, the design of highly-efficient photocatalytic materials for water purification should be optimised to have a practical benefit. Both large surface area and high optical efficiency are required for the high photocatalytic activity of metal oxide films. In this study, the growth of thin ZnO ALD films on self-assembled nanoporous anodic aluminium oxide (AAO) surfaces and porous silicon wafers (MacroPor Template, SmartMembranes) was investigated. AAO samples were obtained by anodizing finely polished aluminium plates in phosphoric acid electrolytes under appropriate electrochemical conditions. The pore size was tuned and tailored by varying the acid molarity to produce a multifunctional nanoporous material with a high surface area. The morphology and the pore size of the samples were characterized by scanning electron microscopy (SEM). The photocatalytic activity of samples coated with ZnO films was evaluated by monitoring the degradation of methylene blue dye in an aqueous solution under UV light irradiation. We have demonstrated that the photocatalytic activity can be greatly increased by changing the porosity of underlying substrates.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA