Low-Temperature H<sub>2</sub>S Detection with Hierarchical Cr-Doped WO<sub>3</sub> Microspheres

Wang, Yanrong; Liu, Bin; Xiao, Songhua; Wang, Xinghui; Sun, Leimeng; Han, Li; Xie, Weixin; Li, Qiuhong; Zhang, Qing; Wang, Taihong

doi:10.1021/acsami.5b12857

Cited by 155 publications

(76 citation statements)

References 67 publications

(90 reference statements)

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“…It indicates that the Pt nanoparticles can induce more oxygen vacancies. It is appreciable that the increasing number of oxygen vacancies can bring about higher absorption of oxygen and reduce activation energy of WO 3 , which is favorable for gas sensing response at low temperature …”

Section: Resultsmentioning

confidence: 99%

Pt Nanoparticles Sensitized Ordered Mesoporous WO₃ Semiconductor: Gas Sensing Performance and Mechanism Study

Ren

Zhou

et al. 2017

Adv Funct Materials

250

173

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In this study, a straightforward coassembly strategy is demonstrated to synthesize Pt sensitized mesoporous WO 3 with crystalline framework through the simultaneous coassembly of amphiphilic poly(ethylene oxide)-b-polystyrene, hydrophobic platinum precursors, and hydrophilic tungsten precursors. The obtained WO 3 /Pt nanocomposites possess large pore size (≈13 nm), high surface area (128 m 2 g −1 ), large pore volume (0.32 cm 3 g −1 ), and Pt nanoparticles (≈4 nm) in situ homogeneously distributed in mesopores, and they exhibit excellent catalytic sensing response to CO of low concentration at low working temperature with good sensitivity, ultrashort response-recovery time (16 s/1 s), and high selectivity. In-depth study reveals that besides the contribution from the fast diffusion of gaseous molecules and rich interfaces in mesoporous WO 3 /Pt nanocomposites, the partially oxidized Pt nanoparticles that chemically and electronically sensitize the crystalline WO 3 matrix, dramatically enhance the sensitivity and selectivity.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.201705268. metal oxides (SMOs), such as WO 3 , [1] ZnO, [2] SnO 2 , [3] In 2 O 3 , [4] have attracted much attention for their wide applications in monitoring gas leakage, air quality, food safety, and medical diagnosis, [5][6][7][8][9] owing to their excellent properties including easy production, low-cost, long-term stability, and compact size. [10] A fast responserecovery dynamics, high sensitivity, and high selectivity are indispensable to highperformance gas sensors based on SMOs because some toxic and flammable gases (e.g., carbon monoxide), are colorless, odorless and tasteless, and extremely poisonous even at low concentrations. Considering that the gas-sensing process strongly relies on surface reactions between target gases and surface-chemisorbed oxygen species on the sensing layers, rational and controlled synthesis of nanomaterials with high surface areas, tailor-designed structure [11][12][13][14] combined with effective catalytic sensitization [15,16] is a promising approach to develop high-performance sensing sensors.SMO nanomaterials with mesoporous structures are promising candidates for gas sensing nanodevices due to their high specific surface area, highly depleted region in thin pore walls, and highly interconnected and adjustable ordered mesopores. [11,12] The high surface area favors the interaction between gas molecules and the solid porous oxide wall as well as the surface catalytic reaction. Moreover, the well-connected channels and a mesoscale (2−50 nm) pore size are advantageous to gas diffusion due to the facile penetration of gas molecules dominated by Knudsen diffusion. [12] To date, mesoporous SMOs can be synthesized through template-free method or templating method. The former includes sol-gel synthesis procedure, [17] spray pyrolysis, [18] and chemical vapor deposition, [3b] which usually lead to materials with ill-defined porous structur...

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Section: Resultsmentioning

confidence: 99%

Pt Nanoparticles Sensitized Ordered Mesoporous WO₃ Semiconductor: Gas Sensing Performance and Mechanism Study

Ren

Zhou

et al. 2017

Adv Funct Materials

250

173

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“…Among the various forms of tungsten materials, tungsten oxides are important semiconductors, which can be used in solar-driven photocatalysis [1][2][3], electrochromism [4], and photochromism [5]. In addition, tungsten oxides are highly sensitive to many kinds of gas, which are considered as one of the most promising gas sensing materials for the detection of NH 3 , H 2 S, NO x , O 3 , H 2 , and so on [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Role of Oxygen Vacancies in the Electrical Properties of WO_3−x Nano/Microrods with Identical Morphology

Shen

Zhao

Wen

et al. 2018

Journal of Nanomaterials

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Tungsten oxide (WO 3−x ) crystalline nano/microrods with identical morphology but different contents of oxygen vacancies were prepared by thermally evaporating fixed amount of WO 3 powder in reductive atmosphere from different amounts of S power at 1150 ∘ C in a vacuum tube furnace, in which both sources were loaded in separate ceramic boat. With increasing amount of S powder, a series of tungsten oxides, WO 3 , WO 2.90 , W 19 O 55 (WO 2.89 ), and W 18 O 49 (WO 2.72 ), could be obtained. And devices were fabricated by screen-printing the obtained WO 3−x crystals on ceramic substrates with Ag-Pd interdigital electrodes. With increasing content of oxygen vacancies, the devices fabricated with WO 3−x crystals present a negative to positive resistance response to relative humidity. Under dry atmosphere, for the devices with increasing , the strong response to light changed from short to long wavelength; under light irradiation, the conducting ability of the devices was enhanced, due to the more efficient separation and transportation of the photogenerated carriers; and under simulated solar irradiation, the photocurrent intensity of the W 18 O 49 device was roughly 8 times, about 500 times, and even 1000 times larger than that of the W 19 O 55 , WO 2.90 , and WO 3 one, respectively. With the versatile optoelectrochemical properties, the obtained WO 3−x crystals have the great potential to prepare various humidity sensors and optoelectrical devices.

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“…6b). [35][36][37] 3.2 Gas sensing properties 3.2.1 Gas-sensing measurement. Gas sensing experiments to 50 ppm hydrogen sulde gases at different temperatures are performed as shown in Fig.…”

Section: Characterization Of Sensor Materialsmentioning

confidence: 99%

A highly selective and sensitive H₂S sensor at low temperatures based on Cr-doped α-Fe₂O₃ nanoparticles

et al. 2019

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Low-Temperature H₂S Detection with Hierarchical Cr-Doped WO₃ Microspheres

Cited by 155 publications

References 67 publications

Pt Nanoparticles Sensitized Ordered Mesoporous WO₃ Semiconductor: Gas Sensing Performance and Mechanism Study

Pt Nanoparticles Sensitized Ordered Mesoporous WO₃ Semiconductor: Gas Sensing Performance and Mechanism Study

Role of Oxygen Vacancies in the Electrical Properties of WO_3−x Nano/Microrods with Identical Morphology

A highly selective and sensitive H₂S sensor at low temperatures based on Cr-doped α-Fe₂O₃ nanoparticles

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Low-Temperature H2S Detection with Hierarchical Cr-Doped WO3 Microspheres

Cited by 155 publications

References 67 publications

Pt Nanoparticles Sensitized Ordered Mesoporous WO3 Semiconductor: Gas Sensing Performance and Mechanism Study

Pt Nanoparticles Sensitized Ordered Mesoporous WO3 Semiconductor: Gas Sensing Performance and Mechanism Study

Role of Oxygen Vacancies in the Electrical Properties of WO3−x Nano/Microrods with Identical Morphology

A highly selective and sensitive H2S sensor at low temperatures based on Cr-doped α-Fe2O3 nanoparticles

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Low-Temperature H₂S Detection with Hierarchical Cr-Doped WO₃ Microspheres

Pt Nanoparticles Sensitized Ordered Mesoporous WO₃ Semiconductor: Gas Sensing Performance and Mechanism Study

Pt Nanoparticles Sensitized Ordered Mesoporous WO₃ Semiconductor: Gas Sensing Performance and Mechanism Study

Role of Oxygen Vacancies in the Electrical Properties of WO_3−x Nano/Microrods with Identical Morphology

A highly selective and sensitive H₂S sensor at low temperatures based on Cr-doped α-Fe₂O₃ nanoparticles