Synthesis of TiO<sub>2</sub>–ZnS nanocomposites <i>via</i> sacrificial template sulfidation and their ethanol gas-sensing performance

Liang, Yuan‐Chang; Xu, Nian-Cih

doi:10.1039/c8ra04157a

Cited by 30 publications

(8 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relatively low operating temperature of SW-0.3-E is due to the introduction of Au NPs, which can remarkably improve the dissociation of oxygen molecules and serve as catalysts decreasing the activation energy during gas sensing process. [42][43][44] The dynamic resistance transition of SW-0.3-E (Figure 5a) and SW-0.3 ( Figure S7, Supporting Information) toward different concentration of ethanol gas (50,100,150,200, and 250 ppb) at the operating temperature of 150 °C reveal that the resistance of the sensors decreased upon injection of the ethanol gas and recovered to its initial value upon replacement with air. The corresponding response of the SW-0.3-E and SW-0.3 based sensors toward different concentration of ethanol gas in the range of 50-250 ppb reveals that both of them possess a good linearity between the response and concentration (Figure 5b).…”

Section: Resultsmentioning

confidence: 99%

Au Nanoparticles Decorated Mesoporous SiO₂–WO₃ Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Zhou

et al. 2020

Small

View full text Add to dashboard Cite

quality monitoring, [4,5] food safety, [6] and disease diagnosis, [7] etc. Among different kinds of gas sensors, semiconducting metal oxides (SMOs)-based gas sensors are one of the most widely used gas sensors, owning to its unique advantages, such as low-cost, fast response, and scalable processing technique. [8-10] Low operating temperature and high sensitivity to low concentration of gases are important parameters of high-performance SMOs-based gas sensors. On one hand, it is well known that the operating temperature of most pristine SMOsbased gas sensors is high (300-450 °C), [9] which is not conducive to miniaturization and integration of devices. [10] In addition, high operating temperature makes SMOs-based gas sensors difficult and dangerous to be applied in wearable and wireless devices. [10,11] On the other hand, in many important applications (e.g., indoor pollution gas warning, exhaled gas analysis, etc.), gas sensors are required to detect target gases (e.g., formaldehyde, acetone, ethanol, etc.) ranging from tens of ppb to hundreds of ppb. [12-15] Conventional powder SMOs materials exhibit low specific surface area and low porosity, which limits the reaction of gas molecules with sensitive materials and the gas diffusion, resulting in poor sensitivity to lowconcentration of gases. [16] Moreover, lowering the operating temperature decreases the concentration of ionized oxygen species adsorbed on the surface of pure SMOs, [9] which further Semiconducting metal oxides-based gas sensors with the capability to detect trace gases at low operating temperatures are highly desired in applications such as wearable devices, trace pollutant detection, and exhaled breath analysis, but it still remains a great challenge to realize this goal. Herein, a multi-component co-assembly method in combination with pore engineering strategy is proposed. By using bi-functional (3-mercaptopropyl) trimethoxysilane (MPTMS) that can co-hydrolyze with transition metal salt and meanwhile coordinate with gold precursor during their co-assembly with PEO-b-PS copolymers, ordered mesoporous SiO 2-WO 3 composites with highly dispersed Au nanoparticles of 5 nm (mesoporous SiO 2-WO 3 /Au) are straightforward synthesized. This multi-component co-assembly process avoids the aggregation of Au nanoparticles and pore blocking in conventional post-loading method. Furthermore, through controlled etching treatment, a small portion of silica can be removed from the pore wall, resulting in mesoporous SiO 2-WO 3 /Au with increased specific surface area (129 m 2 g −1), significantly improved pore connectivity, and enlarged pore window (>4.3 nm). Thanks to the presence of well-confined Au nanoparticles and ε-WO 3 , the mesoporous SiO 2-WO 3 /Au based gas sensors exhibit excellent sensing performance toward ethanol with high sensitivity (R a /R g = 2-14 to 50-250 ppb) at low operating temperature (150 °C).

show abstract

Section: Resultsmentioning

confidence: 99%

Au Nanoparticles Decorated Mesoporous SiO₂–WO₃ Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Zhou

et al. 2020

Small

View full text Add to dashboard Cite

show abstract

“…For the gas sensor applications, one-dimensional (1D) metal oxides usually show better performance in comparison with their thin-film or bulk counterparts because of their high surface-to-volume ratio [3,4,5,6]. In particular, gas sensors based on 1D titanium dioxide (TiO 2 ) nanostructures have received considerable attention because they can be fabricated with diverse chemical and physical methods; moreover, TiO 2 has been shown to be favorable for the detection of diverse harmful gases and volatile organic vapors at elevated temperatures [5,7,8].…”

Section: Introductionmentioning

confidence: 99%

Design of Nanoscaled Surface Morphology of TiO2–Ag2O Composite Nanorods through Sputtering Decoration Process and Their Low-Concentration NO2 Gas-Sensing Behaviors

Liang

Liu

2019

Nanomaterials

Self Cite

View full text Add to dashboard Cite

TiO2–Ag2O composite nanorods with various Ag2O configurations were synthesized by a two-step process, in which the core TiO2 nanorods were prepared by the hydrothermal method and subsequently the Ag2O crystals were deposited by sputtering deposition. Two types of the TiO2–Ag2O composite nanorods were fabricated; specifically, discrete Ag2O particle-decorated TiO2 composite nanorods and layered Ag2O-encapsulated TiO2 core–shell nanorods were designed by controlling the sputtering duration of the Ag2O. The structural analysis revealed that the TiO2–Ag2O composite nanorods have high crystallinity. Moreover, precise control of the Ag2O sputtering duration realized the dispersive decoration of the Ag2O particles on the surfaces of the TiO2 nanorods. By contrast, aggregation of the massive Ag2O particles occurred with a prolonged Ag2O sputtering duration; this engendered a layered coverage of the Ag2O clusters on the surfaces of the TiO2 nanorods. The TiO2–Ag2O composite nanorods with different Ag2O coverage morphologies were used as chemoresistive sensors for the detection of trace amounts of NO2 gas. The NO2 gas-sensing performances of various TiO2–Ag2O composite nanorods were compared with that of pristine TiO2 nanorods. The underlying mechanisms for the enhanced sensing performance were also discussed.

show abstract

“…Oxides in a one-dimensional architecture have the advantage of high sensitivity and fast response/recovery speed due to their high surface-to-volume ratio and great surface activity compared to bulk or thin-film form [7,8,9]. Therefore, the application of one-dimensional WO 3 nanostructures is one of the main strategies for increasing their gas-sensing performances.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Acetone Gas-Sensing Responses of Tapered WO3 Nanorods through Sputtering Coating with a Thin SnO2 Coverage Layer

Liang

Chao

2019

Nanomaterials

Self Cite

View full text Add to dashboard Cite

WO3–SnO2 composite nanorods were synthesized by combining hydrothermal growth of tapered tungsten trioxide (WO3) nanorods and sputter deposition of thin SnO2 layers. Crystalline SnO2 coverage layers with thicknesses in the range of 13–34 nm were sputter coated onto WO3 nanorods by controlling the sputtering duration of the SnO2. The X-ray diffraction (XRD) analysis results demonstrated that crystalline hexagonal WO3–tetragonal SnO2 composite nanorods were formed. The microstructural analysis revealed that the SnO2 coverage layers were in a polycrystalline feature. The elemental distribution analysis revealed that the SnO2 thin layers homogeneously covered the surfaces of the hexagonally structured WO3 nanorods. The WO3–SnO2 composite nanorods with the thinnest SnO2 coverage layer showed superior gas-sensing response to 100–1000 ppm acetone vapor compared to other composite nanorods investigated in this study. The substantially improved gas-sensing responses to acetone vapor of the hexagonally structured WO3 nanorods coated with the SnO2 coverage layers are discussed in relation to the thickness of SnO2 coverage layers and the core–shell configuration of the WO3–SnO2 composite nanorods.

show abstract

Synthesis of TiO₂–ZnS nanocomposites via sacrificial template sulfidation and their ethanol gas-sensing performance

Abstract: TiO2–ZnS core–shell composite nanorods were synthesized by using ZnO as a sacrificial shell layer in a hydrothermal reaction.

Cited by 30 publications

References 26 publications

Au Nanoparticles Decorated Mesoporous SiO₂–WO₃ Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Au Nanoparticles Decorated Mesoporous SiO₂–WO₃ Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Design of Nanoscaled Surface Morphology of TiO2–Ag2O Composite Nanorods through Sputtering Decoration Process and Their Low-Concentration NO2 Gas-Sensing Behaviors

Enhancement of Acetone Gas-Sensing Responses of Tapered WO3 Nanorods through Sputtering Coating with a Thin SnO2 Coverage Layer

Contact Info

Product

Resources

About

Synthesis of TiO2–ZnS nanocomposites via sacrificial template sulfidation and their ethanol gas-sensing performance

Abstract: TiO2–ZnS core–shell composite nanorods were synthesized by using ZnO as a sacrificial shell layer in a hydrothermal reaction.

Cited by 30 publications

References 26 publications

Au Nanoparticles Decorated Mesoporous SiO2–WO3 Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Au Nanoparticles Decorated Mesoporous SiO2–WO3 Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Design of Nanoscaled Surface Morphology of TiO2–Ag2O Composite Nanorods through Sputtering Decoration Process and Their Low-Concentration NO2 Gas-Sensing Behaviors

Enhancement of Acetone Gas-Sensing Responses of Tapered WO3 Nanorods through Sputtering Coating with a Thin SnO2 Coverage Layer

Contact Info

Product

Resources

About

Synthesis of TiO₂–ZnS nanocomposites via sacrificial template sulfidation and their ethanol gas-sensing performance

Au Nanoparticles Decorated Mesoporous SiO₂–WO₃ Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature

Au Nanoparticles Decorated Mesoporous SiO₂–WO₃ Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature