Effect of formaldehyde gas adsorption on the electrical conductivity of Pd-doped TiO2 thin films

Yıldız, Abdullah; Crışan, D.; Drăgan, Nicolae; Iftimie, N.; Florea, D.; Mardare, Diana

doi:10.1007/s10854-011-0324-y

Cited by 9 publications

(3 citation statements)

References 22 publications

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“…Metal oxide gas sensors, ultrasensitive to chemical and electronic sensitization upon the surface adsorption/desorption process, have been explored as an efficient tool for detecting low concentration VOCs [7][8][9]. However, the sensitivity of most compact metal oxide gas sensors needs further enhancement.…”

Section: Introductionmentioning

confidence: 99%

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO₂@TiO₂ nanofiber heteroarchitectures

Chen

Zhang

2020

J. Phys. D: Appl. Phys.

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With the development of society, formaldehyde has gradually become one of the most common air pollutants in urban environments, offices and homes. In this study, the SnO2@TiO2 heterostructure was prepared by an electrospinning technique, in which the TiO2 nanofibers were uniformly coated by the SnO2 nanoparticles. Gas sensors were prepared from this material and gas sensing properties against formaldehyde (HCHO) gas were investigated. The SnO2@TiO2 composite with a mass ratio of 1.5:1 (ST-1.5) has good sensing properties for HCHO under UV irradiation. The sensibility of ST-1.5 to HCHO with the concentration of 100 ppm under UV irradiation reaches 18.32, which is much higher than the amount of 4.5 in dark conditions. Also, the response and recovery times are decreased from 20 s to 13 s and 16 s to 9 s by UV irradiation, respectively. Importantly, the response to HCHO in high humidity environments is also enhanced by UV irradiation. The improved gas-sensing properties of the SnO2@TiO2 can be ascribed to an enhanced separation of photogenerated charge electron and hole, which greatly reduces the charge recombination.

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Section: Introductionmentioning

confidence: 99%

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO₂@TiO₂ nanofiber heteroarchitectures

Chen

Zhang

2020

J. Phys. D: Appl. Phys.

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“…The aforementioned performance enhancement relies on the fact that the sensitivity of a SMO gas sensor is determined by the efficiency of the catalytic reactions that occur on its surface with the gas under detection. , Noble metals, being highly efficient catalysts, can enhance the reactions on gas sensor surfaces by (1) decreasing the activation energy of those sensing reactions, , (2) increasing the electron transfer rate, and (3) providing more specific adsorption sites for oxygen, − all of which are beneficial to the gas-sensing performance . These in turn depend on the atomic-level distribution and electronic state of the noble-metal dopant in SMOs.…”

Section: Introductionmentioning

confidence: 99%

Chemical and Structural Configuration of Pt-Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition

et al. 2019

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Pt doped semiconducting metal oxides and Pt metal clusters embedded in an oxide matrix are of interest for applications such as catalysis and gas sensing, energy storage and memory devices. Accurate tuning of the dopant level is crucial for adjusting the properties of these materials. Here, a novel atomic layer deposition (ALD) based method for doping Pt into In2O3 in specific, and metals in metal oxides in general, is demonstrated. This approach combines alternating exposures of Pt and In2O3 ALD processes in a single 'supercycle', followed by supercycle repetition leading to multilayered nanocomposites. The atomic level control of ALD and its conformal nature make the method suitable for accurate dopant control even on high surface area supports. Oxidation state, local structural environment and crystalline phase of the embedded Pt dopants were obtained by means of X-ray characterization methods and high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In addition, this approach allows characterization of the nucleation stages of metal ALD processes, by stacking those states multiple times in an oxide matrix. Regardless of experimental conditions, a few Pt ALD cycles leads to the formation of oxidized Pt species due to their highly dispersed nature, as proven by X-ray absorption spectroscopy (XAS). Grazing-incidence small-angle X-ray scattering (GISAXS) and highresolution scanning transmission electron microscopy, combined with energy dispersive X-ray spectroscopy (HR-STEM/EDXS) show that Pt is evenly distributed in the In2O3 metal oxide matrix without the formation of clusters. For a larger number of Pt ALD cycles, typ. > 10, the oxidation state gradually evolves towards fully metallic, and metallic Pt clusters are obtained within the In2O3 metal oxide matrix. This work reveals how tuning of the ALD supercycle approach for Pt doping allows controlled engineering of the Pt compositional and structural configuration within a metal oxide matrix.

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“…[11][12][13], and deposition of noble metal on the surface (Pd, Au, Ag, etc.) [14][15][16]. These modification methods mainly must be implemented through sol-gel method [17] and vapor deposition method [18] and so forth.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Property of Mo-Doped Visible-Light Response Titaniumdioxide Photocatalyst

Song

Wei

et al. 2014

Journal of Spectroscopy

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Mo-titaniumdioxide (P25) photocatalyst with visible-light response was prepared with the ammonium molybdate for Mo source and titaniumdioxide for the raw materials by the method of dissolving and calcining. The photocatalysts’ structure was characterized by XRD, XPS, and UV-Vis absorption spectrum and TEM. The photocatalytic activities of Mo-titaniumdioxide were measured by the degradation of methylene blue (MB) under visible-light irradiation. The results showed that Mo characteristic peaks appeared at the point of 235.45 eV, 234.2 eV, 232.3 eV, and 231.1 eV. In Mo-titaniumdioxide crystal lattice, Mo6+had the highest percentage (about 84.08%), indicating that Mo element was inserted into titaniumdioxide crystal lattice and considerable amount of Mo dopant was in the 6+ valence state, which restrained the recombination of electron-hole and had the visible-light photocatalytic activity. Photocatalytic degradation study indicated that the samples prepared at calcination temperature of 500°C were used to degrade MB; after 3 h, the degradation reached up to 80.67%.

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Effect of formaldehyde gas adsorption on the electrical conductivity of Pd-doped TiO2 thin films

Cited by 9 publications

References 22 publications

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO₂@TiO₂ nanofiber heteroarchitectures

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO₂@TiO₂ nanofiber heteroarchitectures

Chemical and Structural Configuration of Pt-Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition

Preparation and Property of Mo-Doped Visible-Light Response Titaniumdioxide Photocatalyst

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Effect of formaldehyde gas adsorption on the electrical conductivity of Pd-doped TiO2 thin films

Cited by 9 publications

References 22 publications

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO2@TiO2 nanofiber heteroarchitectures

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO2@TiO2 nanofiber heteroarchitectures

Chemical and Structural Configuration of Pt-Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition

Preparation and Property of Mo-Doped Visible-Light Response Titaniumdioxide Photocatalyst

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Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO₂@TiO₂ nanofiber heteroarchitectures

Ultraviolet irradiation enhanced formaldehyde-sensing performance based on SnO₂@TiO₂ nanofiber heteroarchitectures