Titania Solid Thin Films Deposited by pp‐MOCVD Exhibiting Visible Light Photocatalytic Activity

Krumdieck, Susan; Gorthy, Rukmini; Land, Johann G.; Gardecka, Aleksandra J.; Polson, Matthew I. J.; Boichot, R.; Bishop, Catherine M.; Kennedy, J.

doi:10.1002/pssa.201700578

Cited by 5 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, at 430-600 °C the rutile starts growing leading to a progressive decrease of the photocatalytic efficiency. Krumdieck et al 17 synthesized TiO 2 films by MOCVD at 375, 450 and 525 °C. The authors analyzed the effects of increasing the growth temperature on the microstructure of films, and its photocatalytic efficiency in the degradation of the methylene blue dye.…”

Section: Effect Of Growth Parameters On the Photocatalytic Performancmentioning

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.

View full text Add to dashboard Cite

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.

show abstract

Section: Effect Of Growth Parameters On the Photocatalytic Performancmentioning

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.

View full text Add to dashboard Cite

show abstract

“…The pp-MOCVD process uses flash vaporization of liquid precursor, and deposition occurs during periodic sharp spikes in vapor pressure 23 . We have previously reported the emergence of fine columnar morphology when the substrate temperature is high enough for pyrolytic carbon deposition and mass transport-controlled growth 24 .…”

Section: Introductionmentioning

confidence: 99%

Nanostructured TiO2 anatase-rutile-carbon solid coating with visible light antimicrobial activity

Krumdieck

Boichot

Gorthy

et al. 2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

TiO2 photocatalyst is of interest for antimicrobial coatings on hospital touch-surfaces. Recent research has focused on visible spectrum enhancement of photocatalytic activity. Here, we report TiO2 with a high degree of nanostructure, deposited on stainless steel as a solid layer more than 10 μm thick by pulsed-pressure-MOCVD. The TiO2 coating exhibits a rarely-reported microstructure comprising anatase and rutile in a composite with amorphous carbon. Columnar anatase single crystals are segmented into 15–20 nm thick plates, resulting in a mille-feuilles nanostructure. Polycrystalline rutile columns exhibit dendrite generation resembling pine tree strobili. We propose that high growth rate and co-deposition of carbon contribute to formation of the unique nanostructures. High vapor flux produces step-edge instabilities in the TiO2, and solid carbon preferentially co-deposits on certain high energy facets. The equivalent effective surface area of the nanostructured coating is estimated to be 100 times higher than standard TiO2 coatings and powders. The coatings prepared on stainless steel showed greater than 3-log reduction in viable E coli after 4 hours visible light exposure. The pp-MOCVD approach could represent an up-scalable manufacturing route for supported catalysts of functional nanostructured materials without having to make nanoparticles.

show abstract

“…Pulsed-pressure metalorganic chemical vapor deposition (pp-MOCVD) has been used to nanoengineer solid TiO 2 coatings (≤17 µm thick) that are composites of anatase, rutile and carbon. The coatings shown in Figure 2 have a rarely-seen columnar morphology composed of single crystal anatase and polycrystalline rutile columns [16]. Anatase columns appear pyramidal at the top and the rough dendritic structures are polycrystalline rutile ( Figure 2).…”

Section: Nanostructured Materials For Coating Applicationsmentioning

confidence: 99%

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

2020

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Titania Solid Thin Films Deposited by pp‐MOCVD Exhibiting Visible Light Photocatalytic Activity

Cited by 5 publications

References 39 publications

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

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

Nanostructured TiO2 anatase-rutile-carbon solid coating with visible light antimicrobial activity

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

Contact Info

Product

Resources

About