WO3 nanowires loaded with cobalt oxide nanoparticles, deposited by a two-step AACVD for gas sensing applications

Navarrete, Eric; Bittencourt, Carla; Noirfalise, Xavier; Umek, Polona; González, Ernesto Rafael; Güell, Frank; Llobet, Eduard

doi:10.1016/j.snb.2019.126868

Cited by 28 publications

(8 citation statements)

References 20 publications

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“…[4,6,7] The other is to merge the preparation of WO 3 film and the loading of catalyst into one step. [8,9] Many methods have been used to prepare WO 3 films, such as PVD, [10][11][12] CVD, [13,14] sol-gel method, [15,16] hydrothermal/ solvothermal method, [17][18][19][20] electrodeposition and anodic oxidation. [21][22][23][24] The hydrothermal/solvothermal method can be used to prepare nanostructured film with simple experimental conditions and low cost.…”

mentioning

confidence: 99%

Structure Design and Performance Research of WO₃ Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Gao

Guo

Nie

et al. 2022

Adv Materials Inter

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air is a kind of hydrogen-sensitive material and can change its color when exposed to hydrogen. This hydrogen gasochromic phenomenon provides a visualized and safer method without electrical signals to detect hydrogen.As a versatile material, WO 3 film can be directly used for photocatalysis and electrochromism without catalyst. Researchers have done a lot of work in these fields. [1,2] However, catalyst loading is essential to observe hydrogen gasochromism of WO 3 film at room temperature. Currently, although many issues regarding the mechanism of WO 3 hydrogen gasochromism have not been fully understood, the processes of adsorption and decomposition of H 2 or O 2 on the surface of the catalyst and the diffusion of H or O atoms between catalyst and WO 3 are widely recognized in different models. The commonly used catalyst materials are Pt and Pd. [3,4] Meanwhile, some researchers also use PdO, PtO x or Pd-Pt alloy as catalysts. [5,6] Usually, there are two ways to load catalyst. One is to prepare WO 3 film first, then load the catalyst on it. [4,6,7] The other is to merge the preparation of WO 3 film and the loading of catalyst into one step. [8,9] Many methods have been used to prepare WO 3 films, such as PVD, [10][11][12] CVD, [13,14] sol-gel method, [15,16] hydrothermal/ solvothermal method, [17][18][19][20] electrodeposition and anodic oxidation. [21][22][23][24] The hydrothermal/solvothermal method can be used to prepare nanostructured film with simple experimental conditions and low cost. Compared with dense film, nanostructured porous film with the high specific surface area often has better catalysis and reaction performance, so the hydrothermal/ solvothermal method is a promising method to prepare nanostructured porous WO 3 film. Before hydrothermal/solvothermal synthesis, many researchers prepare seed layer on the substrate firstly for the consideration of the provision of nucleation sites and good adhesion between substrate and film. A typical process of preparing seed layer includes synthesis of WO 3 sol, spin coating, and annealing. To guarantee the quality of the seed layer, this process has to be repeated several times. As a result, the time-consuming and laborious heat treatment is indispensable for preparing seed layer in the solvothermal synthesis of The time-consuming and laborious heat treatment is indispensable for preparing seed layer in solvothermal synthesis of WO 3 film. Herein, WO 3 film is prepared composed of single crystal WO 3 nanowires on indium tin oxide (ITO) glass assisted with simple and energy-saving electrodeposited seed layer for the first time. The catalyst Pt is sputtered on it for 30 s after WO 3 film is synthesized to form the hydrogen gasochromic film. The film structure is redesigned to improve its hydrogen gasochromic properties further. Before WO 3 film is solvothermally synthesized, Pt is sputtered on seed layer for 15 s, then it is sputtered for 15 s again after WO 3 film is prepared. The Pt sputtered on seed layer greatly changes the morphology of nanowires, makin...

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confidence: 99%

Structure Design and Performance Research of WO₃ Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Gao

Guo

Nie

et al. 2022

Adv Materials Inter

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“…[118] For hydrogen sensing, Pt-functionalized PdO nanowires were also investigated. [119] In other studies, CeO 2 , AgO 2 , and CoOx nanoparticles were employed to decorate SnO 2 and WO 3 nanowires [120][121][122] or Co 3 O 4 nanoparticles were incorporated into In 2 O 3 1D ribbons. [123] A systematic study on formaldehyde sensing with WO 3 nanowires decorated with various metal nanoparticles was performed by Bouchikhi et al and the radar plot reported in Figure 4e demonstrates as compositional modifications (and UV irradiation) allow us to tune the device response.…”

Section: Nanoheterostructures Based On Metal Oxides and Noble Metalsmentioning

confidence: 99%

Advances in Materials and Technologies for Gas Sensing from Environmental and Food Monitoring to Breath Analysis

Milone

Monteduro

Rizzato

et al. 2022

Advanced Sustainable Systems

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Figure 2. a) Pie chart illustrating the use of n-type and p-type metal oxides materials in gas sensing research (reproduced with permission. [23] Copyright 2014, Elsevier B.V.); b) schematics of a typical chemiresistors (e.g., based on WO 3 -films) (reproduced with permission. [55] Copyright 2007, IEEE); c) response of a solid-state impedance NO x gas sensor upon NO exposure (reproduced with permission. [56] Copyright 2003, Elsevier B.V.). d) Illustration of gas sensing through a mesoporous material with different analyte percolation ability (reproduced with permission. [24] Copyright 2013, Royal Society of Chemistry); e) grain size effect in n-type semiconducting metal oxide gas sensors (reproduced with permission under the term of CC-BY license. [57] Copyright 2012, the Authors, published by MDPI); f-h) crystalline ordered mesoporous WO 3 /Pt composites schematic and FESEM images (reproduced with permission. [47] Copyright 2018, Elsevier B.V.); i) typical response curves of In(III)-SnO 2 loaded cubic mesoporous graphitic carbon nitride sensor when exposed to toluene vapors at a working temperature of 200 °C; l,m) response to 50 ppm and 1 ppm toluene gas at 200 °C (reproduced with permission. [53] Copyright 2018, Elsevier B.V.).

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“…1−5 It is also an important material for the industrial synthesis of the scheelite phase such as Ag 2 WO 4 , SrWO 4 , CaWO 4 , etc. 6−8 Currently, many methods have been used to prepare the WO 3 film, such as PVD, 9−11 CVD, 12,13 sol− gel, 14,15 hydrothermal/solvothermal, 16,17 electrodeposition, anodic oxidation, 18,19 and molten salt synthesis. 20,21 Among these methods, the solvothermal method is paid much attention because of its low cost and simple experimental conditions.…”

Section: Introductionmentioning

confidence: 99%

“…WO 3 is a multifunctional material that can be used for hydrocracking catalysts, photocatalysis, electrochromism, gasochromism, etc. − It is also an important material for the industrial synthesis of the scheelite phase such as Ag 2 WO 4 , SrWO 4 , CaWO 4 , etc. − Currently, many methods have been used to prepare the WO 3 film, such as PVD, − CVD, , sol–gel, , hydrothermal/solvothermal, , electrodeposition, anodic oxidation, , and molten salt synthesis. , Among these methods, the solvothermal method is paid much attention because of its low cost and simple experimental conditions. , It has been confirmed that solvothermally synthesized WO 3 films are composed of basic units such as nanowires, nanorods, nanoplates, nanosheets, and so on. Further research indicates that each of the aforementioned basic units is a WO 3 single crystal with a specific growth direction, and the growth direction is varied in different studies, indicating that it is affected by many parameters of the solvothermal process. − As is known to all, besides the growth direction, the shape of a single crystal is also affected by the exposed lattice planes.…”

Section: Introductionmentioning

confidence: 99%

Characterization and Modeling of WO₃ Nanowires Synthesized via the Solvothermal Method: A Proposed 8-Pointed Star Prism Structure

Gao

Guo

et al. 2023

Crystal Growth & Design

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The solvothermal method is a popular approach for preparing multifunctional WO3 films. In this study, a WO3 film composed of nanowires with diameters of 40–50 nm and lengths of 400 nm to 1 μm was prepared on indium–tin oxide (ITO) glass via the solvothermal process. Transmission electron microscopy (TEM) analysis confirmed that each WO3 nanowire is a monoclinic single crystal with a [002]-selective growth direction. By analyzing the scanning electron micrography (SEM) images at ultrahigh magnifications and observing that the fast Fourier transform (FFT) images of all nanowires were identical, an 8-pointed star prism model was proposed for the morphology of WO3 nanowires. Based on this model, the exposed crystal planes on the outer surface of each WO3 single crystal are supposed to be {120} and {210}, thereby forming an 8-pointed star prism. Finally, the model was validated through focused ion beam (FIB) and TEM assessments. This study deepens our understanding of the morphology of solvothermally synthesized WO3 nanowires and may open up a window for future research on the subject.

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WO3 nanowires loaded with cobalt oxide nanoparticles, deposited by a two-step AACVD for gas sensing applications

Cited by 28 publications

References 20 publications

Structure Design and Performance Research of WO₃ Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Structure Design and Performance Research of WO₃ Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Advances in Materials and Technologies for Gas Sensing from Environmental and Food Monitoring to Breath Analysis

Characterization and Modeling of WO₃ Nanowires Synthesized via the Solvothermal Method: A Proposed 8-Pointed Star Prism Structure

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WO3 nanowires loaded with cobalt oxide nanoparticles, deposited by a two-step AACVD for gas sensing applications

Cited by 28 publications

References 20 publications

Structure Design and Performance Research of WO3 Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Structure Design and Performance Research of WO3 Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Advances in Materials and Technologies for Gas Sensing from Environmental and Food Monitoring to Breath Analysis

Characterization and Modeling of WO3 Nanowires Synthesized via the Solvothermal Method: A Proposed 8-Pointed Star Prism Structure

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Structure Design and Performance Research of WO₃ Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Structure Design and Performance Research of WO₃ Hydrogen Gasochromic Film Prepared by Solvothermal Synthesis Assisted with Electrodeposition of Seed Layer

Characterization and Modeling of WO₃ Nanowires Synthesized via the Solvothermal Method: A Proposed 8-Pointed Star Prism Structure