Gas Sensor Based on 3-D WO3 Inverse Opal: Design and Applications

Xing, Ruiqing; Du, Youwei; Zhao, Xiaonan; Zhang, Xiu

doi:10.3390/s17040710

Cited by 22 publications

(13 citation statements)

References 42 publications

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“…Porous materials have been intensively studied for several decades because of their versatile applications, including as catalytic materials, thermal insulators, sound absorbers, coating materials for water-repelling surfaces, sensors, and filters or membranes [8][9][10][11][12][13]. Among these various application areas, porous materials with high surface to volume ratio, and ultrahigh adsorption capacity, have been adopted as adsorbents for toxic chemicals [14].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Porous Silica Particles for the Adsorption of Organic Dye in Aqueous Medium

Cho¹,

Jeong²,

Nam³

2020

Korean J. Met. Mater.

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This study investigated the removal of the organic dye like methylene blue using porous particles in a batch adsorption process. Porous silica microparticles were synthesized with macropores or meso-macropores and used as adsorbent particles. The hierarchically porous structures with additional mesopores were found to be more effective adsorbent than simple macroporous particles. The size of the macropores affected the adsorption capacity of the porous particles, and smaller pore size resulted in a larger amount of organic dye being adsorbed on the particle surface, due to increased surface area. Silica microparticles with wrinkled surfaces were also tested, and their adsorption capacities were studied in relation to their morphologies. Unlike previous studies using mesoporous silica as adsorbents, in this study the methylene blue adsorption kinetics could be explained by the second to fourth order reaction, implying that faster removal of dye molecules is possible compared to photocatalytic reactions, with first order kinetics. The higher order kinetics can be advantageous, providing a faster removal rate, compared to the conventional photocatalytic removal of dyes and other adsorbents.

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Section: Introductionmentioning

confidence: 99%

Synthesis of Porous Silica Particles for the Adsorption of Organic Dye in Aqueous Medium

Cho¹,

Jeong²,

Nam³

2020

Korean J. Met. Mater.

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“…Semiconducting metal oxides possess great potential as gas‐sensing materials, because the chemical interactions between gas molecules and their surfaces can lead to changes of the electrical conductivity. As a typical n‐type semiconductor, WO 3 has been considered as promising material for fabricating gas sensors in various applications such as in atmospheric safety, for example, detecting indoor air pollutants, monitoring the toxic, flammable, or explosive gases in mine . Other applications include medical diagnostics, such as the evaluation of exhaled acetone …”

Section: Introductionmentioning

confidence: 99%

Pore Engineering of Mesoporous Tungsten Oxides for Ultrasensitive Gas Sensing

Zhou

Luo

et al. 2018

Adv Materials Inter

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between gas molecules and their surfaces can lead to changes of the electrical conductivity. As a typical n-type semiconductor, WO 3 has been considered as promising material for fabricating gas sensors in various applications such as in atmospheric safety, for example, detecting indoor air pollutants, monitoring the toxic, flammable, or explosive gases in mine. [1] Other applications include medical diagnostics, such as the evaluation of exhaled acetone. [2] Considerable efforts have been made to synthesize WO 3 nanomaterials with highly porous structure, large surface area, and crystalline framework. [3] However, conventional synthesis methods, such as chemical vapor deposition, [4] spray pyrolysis, [5] and precipitation reactions, [6] usually give rise to nanoparticles with ill-defined structure, low surface area, which are not favorable for gas sensing applications. Soft-templating synthesis based on surfactants or amphiphilic block copolymers as the template and porogen have been developed for production of mesoporous materials with diverse compositions, and thanks to the versatile and flexible supramolecular coassembly, these methods allow a flexible and efficient control over pore size, pore structure, pore interconnection and so on. Up to now, ordered mesoporous WO 3 with monomodal mesopores have been synthesized by surfactant-templating methods. [7] Although the obtained ordered mesoporous materials exhibit crystalline structure, they have monomodal The mesoporous tungsten oxides have shown great potential in various fields, including energy storage and conversion, catalysis, and gas sensor, because they have ordered porous architectures and unique semiconducting property for host-guest interaction. Most of the reported mesoporous tungsten oxides have monomodal mesopores, which are not favorable for the mass diffusion and host-guest interactions. To date, it still remains a great challenge to synthesize ordered mesoporous WO 3 with bimodal or hierarchical pores and crystalline frameworks. Herein, a pore engineering strategy is demonstrated for the synthesis of ordered mesoporous WO 3 with well-connected bimodal pores, and crystalline pore walls by using hydrophilic resols as the sacrificial carbon source which can interact preferentially with poly(ethylene oxide) (PEO) domains and serves a glue to bridge the tungsten species and poly(ethylene oxide)-block-polystyrene block copolymers. The obtained ordered mesoporous tungsten oxide materials possess dual mesopore size (5.8 and 15.8 nm), high surface area (128 m 2 g −1 ), large window size (7.7 nm), and highly crystalline mesostructure. The dual mesoporous WO 3 -based gas sensor exhibits significantly excellent gas sensing performance toward H 2 S with a rapid response (3 s) and recovery (14 s) even at low concentration (0.2 ppm), and high selectivity, which is much better than previously reported WO 3 -based sensors.

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“…[22][23][24] Acetone is an important solvent for material synthesis, but it can bring about damage to the central nervous system, eyes and noses at high concentrations ($173 ppm). 25 Although gas sensors have already been reported for the detection acetone based on pristine WO 3 nanostructures, such as porous architectures, 26 nanocrystals, 27 nanotubes, 28 nano-bers, 29 inverse opal, 30 shells, 31 and nanosheets, 32 further studies on WO 3 -based sensors are still needed.…”

Section: Introductionmentioning

confidence: 99%

Porous NiO–WO₃ heterojunction nanofibers fabricated by electrospinning with enhanced gas sensing properties

Zhang

Liu

et al. 2017

RSC Adv.

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A series of NiO-WO 3 composite nanofibers with different molar ratios (Ni/W ¼ 0%, 1%, 3% and 5%) were fabricated based on an electrospinning and calcination technique. The gas sensing performances of sensors based on the as-produced nanofibers were studied towards acetone in detail. Compared with the pure WO 3 nanofibers, the porous NiO-WO 3 composite nanofibers exhibited higher sensitivity, faster response, and shorter recovery time towards acetone. Particularly, the 3 mol% NiO-WO 3 heterojunction nanofibers demonstrated the largest sensitivity, exhibiting a prominent value of 22.5 under 100 ppm acetone at the operating temperature of 375 C, which is almost 2.1 times larger than that of the pure WO 3 nanofibers. Moreover, the 3 mol% NiO-WO 3 heterojunction nanofibers also exhibited excellent selectivity and long-term stability to acetone. The combined effects including the formation of p-n heterojunctions between NiO and WO 3 , high oxygen species absorbing capacity, and special porous structural features with high surface area and small grain size, contributed to the enhanced sensing properties of the 3 mol% NiO-WO 3 composite nanofibers. These attractive gas sensing properties enable the NiO-WO 3 heterojunction nanofibers to be a promising material for application in gas sensors.

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Gas Sensor Based on 3-D WO3 Inverse Opal: Design and Applications

Cited by 22 publications

References 42 publications

Synthesis of Porous Silica Particles for the Adsorption of Organic Dye in Aqueous Medium

Synthesis of Porous Silica Particles for the Adsorption of Organic Dye in Aqueous Medium

Pore Engineering of Mesoporous Tungsten Oxides for Ultrasensitive Gas Sensing

Porous NiO–WO₃ heterojunction nanofibers fabricated by electrospinning with enhanced gas sensing properties

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Gas Sensor Based on 3-D WO3 Inverse Opal: Design and Applications

Cited by 22 publications

References 42 publications

Synthesis of Porous Silica Particles for the Adsorption of Organic Dye in Aqueous Medium

Synthesis of Porous Silica Particles for the Adsorption of Organic Dye in Aqueous Medium

Pore Engineering of Mesoporous Tungsten Oxides for Ultrasensitive Gas Sensing

Porous NiO–WO3 heterojunction nanofibers fabricated by electrospinning with enhanced gas sensing properties

Contact Info

Product

Resources

About

Porous NiO–WO₃ heterojunction nanofibers fabricated by electrospinning with enhanced gas sensing properties