Microstructure and elastic properties of atomic layer deposited TiO2 anatase thin films

Borgese, Laura; Bontempi, Elza; Gelfi, Marcello; Depero, Laura E.; Goudeau, P.; Géandier, Guillaume; Thiaudière, Dominique

doi:10.1016/j.actamat.2011.01.032

Cited by 32 publications

(13 citation statements)

References 37 publications

(53 reference statements)

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“…The surface micrograph of different deformation areas remain, whereas at higher T d (450°C and 500°C) the deformation is homogenous over the surface. At low T d , the diversity in mechanical responses is probably linked to small variations in the Young's modulus as a function of crystallographic orientation [45]. At high T d , we link the decrease in the diversity of deformation areas to the general decrease in the grain size, which means that what is probed at higher T d is the mechanical response of a group of nanostructured tree-like columns with different crystallographic planes.…”

Section: Morphologymentioning

confidence: 79%

TiO2 nanotree films for the production of green H2 by solar water splitting: From microstructural and optical characteristics to the photocatalytic properties

Miquelot

Debieu

Rouessac

et al. 2019

Applied Surface Science

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Green H 2 production by solar water splitting relies entirely on the intrinsic properties of the photocatalyst. In this study the impact of these intrinsic properties on the photocatalytic activity of anatase TiO 2 , the quintessential component of state of the art photocatalytic systems was explored at the nanoscale. The exploration involved a holistic microstructural and optical characterization of fully crystallized anatase thin films synthetized by metalorganic chemical vapor deposition. A combination of electron microscopy, spectroscopic ellipsometry, and infrared spectroscopy revealed that when the deposition temperature increased, the morphology evolved from dense to porous and columnar nanostructures. Interestingly, the columns with a complex, tree-like nanostructure photogenerated 18 times more H 2 than the densest sample. This result shows that the beneficial effect of the morphological nano-complexification and crystallographic diversification of the exchange facets on the photocatalytic performance outweighs the detrimental aspects inherent to this evolution, namely the drop of the charge carrier transport and the increase of residual stress. 1. Introduction Research on renewable energy is vital in the current context of global warming and societies that rely on high energy consumption. Hydrogen is a promising source of renewable energy and catalyzed solar water splitting (SWS) is a carbon-free method to produce it. Numerous materials have been tested to catalyze this reaction [1,2]. Among them, TiO 2-because it is non-toxic, chemically stable, abundant and affordable has been widely investigated as a photocatalytic material since Fujishima and Honda's seminal work [3-8]. Despite its high energy band-gap (3.2 eV), crystalline anatase TiO 2 shows attractive opto-electronic properties. It is an indirect semiconductor with a long exciton lifetime [9,10]; it has a conduction band minimum energy level below the redox potential of H+/H 2 (0 V vs. NHE) and a valence band maximum energy level above the redox potential of O 2 /H 2 O (+1.23 V vs. NHE) [11,12].

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Section: Morphologymentioning

confidence: 79%

TiO2 nanotree films for the production of green H2 by solar water splitting: From microstructural and optical characteristics to the photocatalytic properties

Miquelot

Debieu

Rouessac

et al. 2019

Applied Surface Science

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“…3. Young's modulus and hardness of the films increase with the decreasing O 2 gas flow rate, confirming the formation of denser microstructures and lower levels of porosity in the films [18,19]. Plasma assisted samples have enhanced Young's modulus and hardness readings compared to those without plasma treatment, indicating formation of denser microstructures [18,19].…”

Section: Resultsmentioning

confidence: 56%

“…Young's modulus and hardness of the films increase with the decreasing O 2 gas flow rate, confirming the formation of denser microstructures and lower levels of porosity in the films [18,19]. Plasma assisted samples have enhanced Young's modulus and hardness readings compared to those without plasma treatment, indicating formation of denser microstructures [18,19]. For the photocatalytic analysis, the Langmuir-Hinshelwood pseudo-first-order kinetics model is generally used for low dye concentrations [20]: where C 0 is the original MB concentration, C is the concentration at time t,k is the pseudo-first-order rate constant, C a is the concentration after adsorption.…”

Section: Resultsmentioning

confidence: 65%

TiO 2 films prepared using plasma ion assisted deposition for photocatalytic application

Zhao

Child

Gibson

et al. 2014

Materials Research Bulletin

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“…A major advantage of laboratory prepared samples by ALD is that the thin film thickness (directly proportional to the mass by material density and surface area) is directly related to the number of cycles, a process parameter that can be determined in advance. Because of the experience of Chem4Tech research group depositing titania at low temperature by means of ALD [23], it was chosen as the reference material.…”

Section: Methodsmentioning

confidence: 99%

Airborne particulate matter (PM) filter analysis and modeling by total reflection X-ray fluorescence (TXRF) and X-ray standing wave (XSW)

Borgese

Salmistraro

Gianoncelli

et al. 2012

Talanta

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This work is presented as an improvement of a recently introduced method for airborne particulate matter (PM) filter analysis [1]. X-ray Standing Wave (XSW) and Total reflection X-Ray Fluorescence (TXRF) were performed with a new dedicated laboratory instrumentation. The main advantage of performing both XSW and TXRF, is the possibility to distinguish the nature of the sample: if it is a small droplet dry residue, a thin film like or a bulk sample; and to select the angle of total reflection to make TXRF measurements. Finally, the possibility to switch the X-ray source allows to measure with more accuracy lighter and heavier elements (with a a change in X-ray anode, for example from Mo to Cu). The aim of the present study is to lay the theoretical foundation of the new proposed method for airborne PM filters quantitative analysis improving the accuracy and efficiency of quantification by means of an external standard. The theoretical model presented and discussed demonstrated that airborne PM filters can be considered as thin layers. A set of reference samples is prepared in laboratory and used to obtain a calibration curve. Our results demonstrate that the proposed method for quantitative analysis of air PM filters is affordable and reliable without the necessity to digest filters to obtain quantitative chemical analysis, and that the use of XRW improve the accuracy of TXRF analysis.

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Microstructure and elastic properties of atomic layer deposited TiO2 anatase thin films

Cited by 32 publications

References 37 publications

TiO2 nanotree films for the production of green H2 by solar water splitting: From microstructural and optical characteristics to the photocatalytic properties

TiO2 nanotree films for the production of green H2 by solar water splitting: From microstructural and optical characteristics to the photocatalytic properties

TiO 2 films prepared using plasma ion assisted deposition for photocatalytic application

Airborne particulate matter (PM) filter analysis and modeling by total reflection X-ray fluorescence (TXRF) and X-ray standing wave (XSW)

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