Characterization of photocatalytic, wetting and optical properties of TiO 2 thin films and demonstration of uniform coating on a 3-D surface in the mass transport controlled regime

Krumdieck, Susan; Gorthy, Rukmini; Gardecka, Aleksandra J.; Lee, Darryl; Miya, S.; Talwar, Sam Davies; Polson, Matthew I. J.; Bishop, Catherine M.

doi:10.1016/j.surfcoat.2016.11.064

Cited by 21 publications

(24 citation statements)

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“…The pattern also shows that the anatase phase exhibits a strong [220] growth texture. This is consistent with previous studies of pp-MOCVD films [14,18,20,27].…”

Section: Phase and Composition Of Tio2 Coatings Prepared By Pp-mocvdsupporting

confidence: 94%

“…Solvent and reactant product vapors are evacuated into a liquid N 2 cold trap. At high temperatures (>500 • C) the reactor works in the mass-transport controlled regime with high precursor-arrival rate to the substrate surface during the peak of the pressure pulse [20]. The pulsed-pressure cycle is typically 6 seconds with less than 0.5 seconds of pressure rise, and 5 seconds of pump-down [21].…”

Section: Pulsed-pressure Mocvd Technologymentioning

confidence: 99%

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Process-Induced Nanostructures on Anatase Single Crystals via Pulsed-Pressure MOCVD

2020

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The recent global pandemic of COVID-19 highlights the urgent need for practical applications of anti-microbial coatings on touch-surfaces. Nanostructured TiO 2 is a promising candidate for the passive reduction of transmission when applied to handles, push-plates and switches in hospitals.Here we report control of the nanostructure dimension of the mille-feuille crystal plates in anatase columnar crystals as a function of the coating thickness. This nanoplate thickness is key to achieving the large aspect ratio of surface area to migration path length. TiO 2 solid coatings were prepared by pulsed-pressure metalorganic chemical vapor deposition (pp-MOCVD) under the same deposition temperature and mass flux, with thickness ranging from 1.3-16 µm, by varying the number of precursor pulses. SEM and STEM were used to measure the mille-feuille plate width which is believed to be a key functional nano-dimension for photocatalytic activity. Competitive growth produces a larger columnar crystal diameter with thickness. The question is if the nano-dimension also increases with columnar crystal size. We report that the nano-dimension increases with the film thickness, ranging from 17-42 nm. The results of this study can be used to design a coating which has co-optimized thickness for durability and nano-dimension for enhanced photocatalytic properties.

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“…The pattern also shows that the anatase phase exhibits a strong [220] growth texture. This is consistent with previous studies of pp-MOCVD films [14,18,20,27].…”

Section: Phase and Composition Of Tio2 Coatings Prepared By Pp-mocvdsupporting

confidence: 94%

Section: Pulsed-pressure Mocvd Technologymentioning

confidence: 99%

Process-Induced Nanostructures on Anatase Single Crystals via Pulsed-Pressure MOCVD

2020

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“…It can be observed as a dense film with columnar structure (Figure 6b). Results presented by Krumdieck et al [48] showed that the increase of the thickness of the films caused a decreased of the roughness, similar trend with the values exhibited in the present work. The results clearly show that the increase of the growth time ( Table 1) caused an increase in the film thickness, as evidenced by Antunes et al [49].…”

Section: Titanium Dioxide -Materials For a Sustainable Environment 216supporting

confidence: 92%

Titanium Dioxide Films for Photocatalytic Degradation of Methyl Orange Dye

Bento¹,

Pillis²

2018

Titanium Dioxide - Material for a Sustainable Environment

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The aim of this work was to characterize and evaluate the influence of the thickness on the photocatalytic efficiency of titanium dioxide thin films on the degradation of methyl orange dye under UV light irradiation. The films of 280 and 468 nm thick were deposited on borosilicate substrates at 400°C by the MOCVD technique using titanium isoproxide IV as precursor. XRD analyses showed the formation of anatase-TiO 2 phase. Crosssectional FE-SEM images show that the films presented a dense columnar structure and grown perpendicularly to the substrate surface. The photocatalytic activity of the catalysts was studied using UV-vis spectrophotometry The TiO 2 film with 468 nm of thickness presented higher photocatalytic activity exhibiting 69% of dye degradation. The increase of grain size and thickness of the films promoted an improvement of photocatalytic efficiency.

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“…Metalorganic chemical vapor deposition technique (MOCVD), a specific area of CVD, is an attractive process for the growth of TiO 2 films, since it provides improvements in uniformity, presents high growth rates, allows the coating of substrates with complex geometries, and increases the range of substrates used, because in this process lower growth temperatures are used comparing to conventional CVD. [12][13][14] MOCVD process also allows a good control of the films thickness during their growth, promoting the…”

Section: Introductionmentioning

confidence: 99%

Effect of Growth Parameters on the Photocatalytic Performance of TiO2 Films Prepared by MOCVD

Marcello¹,

Corrêa²,

Bento³

et al. 2020

J. Braz. Chem. Soc.

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The present study evaluated the main factors that influence the photocatalytic activity of titanium dioxide (TiO 2 ) films grown by metalorganic chemical vapor deposition (MOCVD) at 400 and 500 °C, in different growth times. The photocatalytic behavior was analyzed by measuring the methyl orange dye degradation at different pH values. Structural and morphological characteristics, and the recyclability of the catalysts for several cycles were also investigated. Anatase phase was identified in all films. The higher photodegradation performances were obtained at acidic pH. The results demonstrated that the photocatalyst thickness is an important parameter in heterogenous photocatalysis. The best photocatalytic result occurred for the 395 nm-thick TiO 2 film grown at 400 °C, which presented 65.3% of the dye degradation under UV light. The recyclability experiments demonstrated that the TiO 2 films grown by MOCVD present a great stability after several photocatalytic cycles, which allows their practical application for water treatment with high efficiency.

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Characterization of photocatalytic, wetting and optical properties of TiO 2 thin films and demonstration of uniform coating on a 3-D surface in the mass transport controlled regime

Cited by 21 publications

References 50 publications

Process-Induced Nanostructures on Anatase Single Crystals via Pulsed-Pressure MOCVD

Process-Induced Nanostructures on Anatase Single Crystals via Pulsed-Pressure MOCVD

Titanium Dioxide Films for Photocatalytic Degradation of Methyl Orange Dye

Effect of Growth Parameters on the Photocatalytic Performance of TiO2 Films Prepared by MOCVD

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