SENSORS AND ACTUATORS B-CHEMICAL
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2020
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IF 7.1
Boxuan Yang,Zheng Zhang,Chen Tian,Wenjing Yuan,Zhongqiu Hua,Shurui Fan,Yi Wu,Xuemin Tian
Gas sensors based on Pd-loaded SnO 2 were prepared with printed zeolite films on the top of the sensor layer to enhance selective response to methane. As expected, Pd-loaded SnO 2 has a sensitive response to CH 4 and VOCs, such as ethanol and acetone vapors. Pt catalyst was dispersed onto the surface to promote the catalytic activity of zeolite. According to the catalytic characterizations, it was indicated that interfered gases, CO and ethanol were catalytically oxidized into CO 2 and water vapor. Whereas the catalytic combustion of methane is a negligible and sensitive response to the interested analyte was significantly promoted. Thus, the selective response to CH 4 was greatly improved even in a mixture of CO and VOCs. Based on the power-law response to oxygen, it was found that the resistive responses of all sensors were highly oxygen-dependent, suggesting that oxygen adsorbates on the surface were involved in the sensing process and no difference with zeolite coated sensors. Thus, it can be concluded that zeolite films printed onto the sensing layer surface serve as a catalytic filter and responsible for the enhanced sensitive and selective response of methane.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Li Xiao,Shengrui Xu,Geng Yu,Shantang Liu
A novel gas microsensor combining SnO 2 submicron/nanostructured porous sensitive film with Micro-Electro-Mechanical systems (MEMS) microheater was successfully fabricated. The film was made of hierarchically mixed Pd/SnO 2 (HM-PTO) composites composed of Pd/SnO 2 hollow submicrospheres (Pd/SnO 2 -HSs) and Pd/SnO 2 nanoparticles (Pd/SnO 2 -NPs) deposited on the microheater platform using the microdispensing method. The as-prepared HM-PTO sensors exhibited high sensitivities, fast response/recovery rates, good selectivity, reliable reversibility, and relevant stability towards ethanol at low power consumption. The resulting superior sensing performances were attributed to the unique hierarchical structure. The internal void architecture of Pd/SnO 2 -HSs provided large specific surface areas, proper mesopore size distribution, large number of active adsorption/interaction sites, as well as promoted the chemisorption and dissociation of gas molecules due Pd-doping to yield superior gas response. In particular, the nano-sized SnO 2 particles ensured the uniform deposition of the materials to yield enhanced local conductivities, and possibly faster phase transfer reactions responsible for the extremely good response/recovery performance. This simple fabrication procedure combined with high sensing performances look promising for the development of hierarchical morphologies of novel materials for gas sensing applications.
研究领域:
材料科学
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传感器技术
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2017
·
IF 4.339
Miaomiao Liu,Weiqiang Tang,Yisheng Xu,Hongbo Yu,Hongfeng Yin,Shuangliang Zhao,Shenghu Zhou
Pd-SnO 2 heteroaggregate nanocatalysts were synthesized by in-situ transformation of PdSn bimetallic nanoparticles on alumina. The PdSn bimetallic nanoparticles were prepared by co-reduction of Pd and Sn precursors. The obtained PdSn nanoparticles possibly have a core-shell like structure with Pd cores and Sn-rich shells due to the fast reduction of Pd precursors. The Pd-SnO 2 /Al 2 O 3 heteroaggreagte nanocatalysts were synthesized by calcination of PdSn/Al 2 O 3 in air followed by H 2 reduction. Various characterization techniques, such as HRTEM, XRD and XPS, were used to characterize the PdSn and Pd-SnO 2 . The Pd 3 -(SnO 2 ) 1 /Al 2 O 3 heteroaggreagte nanocatalysts with a ratio of Pd/Sn of 3/1 illustrated enhanced catalytic performances for p -nitroacetophenone and p -nitrobenzaldehyde hydrogenations relative to monometallic Pd nanocatalysts. Theoretical calculations using density functional theory suggested that Pd-SnO 2 facilitates the adsorption of reactants in a higher degree than that of products, thus enhancing the catalytic activity even with partial coverage of Pd surfaces with SnO 2 . The blockage effect of SnO 2 on Pd surfaces is speculated to enhance the catalytic selectivity for p -nitroacetophenone and p -nitrobenzaldehyde hydrogenations over Pd-SnO 2 heteroaggregate nanocatalysts.
研究领域:
催化化学
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材料科学
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理论计算
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DOI
高影响因子
ACS Applied Energy Materials
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2019
·
IF 0
Ting Qu,Qiang Tan,Yingjie Chen,Liting Liu,Shengwu Guo,Yuanzhen Chen,Yan Liu,Sai Li,Yongning Liu
Direct alcohol fuel cell technology (DAFC) has gained significant interest recently as it is a green energy technology with a low/zero pollution emission. Nevertheless, the sluggish kinetics of the electrocatalysis process and the high cost of anode catalysts still impede the wide application of DAFC. Moreover, the limited understanding of the reaction mechanism restrains the development of anode catalysts. Here, we have prepared a Pd-(SnO2@C)/C catalyst and highlighted a strategy to demonstrate the effects of active oxygen-contained species and electronic interaction, which are identified to have a synergistic effect. The as-prepared Pd-(SnO2@C)/C catalyst showed remarkable activity and stability for EOR and MOR in alkaline media. It also had an encouraging performance in a polymer fiber membrane-based alkaline DAFC, where a NiCo2O4 catalyst was used for the oxygen cathode. Combined with the theoretical analysis and the experimental research results, this study reveals that the electronic interaction is the dominant mechanism in the synergistic effect, which provides theoretical guidance and technical support for the preparation of the next generation of high catalytic activity and high stability anode catalysts of DAFC.
研究领域:
电化学
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催化
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能源材料
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燃料电池
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产品关联
DOI
Materials
·
2022
·Vol. 15
·期 4
·1367
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IF 3.748
Fubing Gui,Yong Huang,Menghan Wu,Xilai Lu,Yongming Hu,Wanping Chen
A high long-term stability is crucial for room-temperature gas-sensitive metal oxide semiconductors (MOSs) to find practical applications. A series of Pd-SnO2mixtures with 2, 5, and 10 wt% Pd separately were prepared from SnO2and Pd powders. Through pressing and sintering, Pd-SnO2composite nanoceramics have been successfully prepared from the mixtures, which show responses of 50, 100, and 60 to 0.04% CO-20% O2-N2at room temperature for samples of 2, 5, and 10 wt% Pd, respectively. The room-temperature CO-sensing characteristics were degraded obviously after dozens of days’ aging for all samples. For samples of 5 wt% Pd, the response to CO was decreased by a factor of 4 after 20 days of aging. Fortunately, some rather mild heat treatments will quite effectively reactivate those aged samples. Heat treatment at 150 °C for 15 min in air tripled the response to CO for a 20 days-aged sample of 5 wt% Pd. It is proposed that the deposition of impurity gases in air on Pd in Pd-SnO2composite nanoceramics has resulted in the observed aging, while their desorption from Pd through mild heat treatments leads to the reactivation. More studies on aging and reactivation of room-temperature gas sensitive MOSs should be conducted to achieve high long-term stability for room-temperature MOS gas sensors.Keywords:CO;sensors;SnO2;aging;heat treatment;recover
研究领域:
材料科学
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传感器技术
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2026
·
IF 6.7
Bo Yang,Ziqi Wang,Chuan Luo,Bingqin Lv,Zhengang Zhao
The rapid and accurate detection of carbon monoxide (CO) is essential for environmental safety and human health. In this work, a series of sponge-like porous SnO 2 nanocomposites with varying Pd doping contents (0–5.0 at%) were synthesized via a one-step hydrothermal method. Their CO sensing properties were systematically investigated. The results reveal that Pd is incorporated into the SnO 2 lattice in the form of highly dispersed Pd 2+ species. These species facilitate the formation of a three-dimensional porous network interconnected by SnO 2 nanocrystals of approximately 5 nm in size. Gas sensing tests demonstrate that the sensor with a Pd doping content of 1.0 at% exhibits the highest response value ( R a / R g = 64 ) to 100 ppm CO at an optimal operating temperature of 150 °C, with a fast response time of 7 s and high selectivity to CO. Moreover, this sensor achieves a low detection limit of 1.455 ppm and maintains a detectable response over a 30-day testing period. X-ray photoelectron spectroscopy (XPS) analysis and density functional theory (DFT) calculations reveal that Pd doping not only introduces abundant oxygen vacancies but also activates CO molecules through strong chemisorption (adsorption energy of −1.13 eV), thereby accelerating the surface oxidation reaction kinetics. This structural design, combined with the Pd-induced catalytic enhancement (e.g., oxygen vacancy creation and strong chemisorption), provides a new strategy for developing high-performance low-temperature CO sensors.
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DOI
PubMed
高影响因子
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