ANALYTICAL CHEMISTRY
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2013
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IF 5.695
Ruixue Wang,Geli Li,Yongqiang Dong,Yuwu Chi,Guonan Chen
Silica aerogels functionalized with strongly fluorescent carbon quantum dots were first prepared and used for simple, sensitive, and selective sensing of NO2 gas. In the presence of ethanol, homemade silica aerogels with a large specific surface area of 801.17 m2/g were functionalized with branched polyethylenimine-capped quantum dots (BPEI-CQDs) with fluorescence quantum yield higher than 40%. The prepared porous CQD-aerogel hybrid material could maintain its excellent fluorescence (FL) activity in its solid state. The FL of CQD-aerogel hybrid material could be selectively and sensitively quenched by NO2 gas, suggesting a promising application of the new FL-functionalized aerogels in gas sensing.
研究领域:
材料科学
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环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Jie Li,Haoran Song,Tao Luo,Yan Cao,Linfeng Zhang,Qun Zhao,Zhanchao Li,Xuewei Hu,Junjie Gu,Senlin Tian
Exposure to ozone (O 3 ) and nitrogen dioxide (NO 2 ) are related to pulmonary dysfunctions and various lung diseases, but the underlying biochemical mechanisms remain uncertain. Herein, the effect of inhalable oxidizing gas pollutants on the pulmonary surfactant (PS, extracted from porcine lungs), a mixture of active lipids and proteins that plays an important role in maintaining normal respiratory mechanics , is investigated in terms of the interfacial chemistry using in-vitro experiments; and the oxidative stress induced by oxidizing gases in the simulated lung fluid (SLF) supplemented with the PS is explored. The results showed that O 3 and NO 2 individually increased the surface tension of the PS and reduced its foaming ability; this was accompanied by the surface pressure-area isotherms of the PS monolayers shifting toward lower molecular areas, with O 3 exhibiting more severe effects than NO 2 . Moreover, both O 3 and NO 2 produced reactive oxygen species (ROS) resulting in lipid peroxidation and protein damage to the PS. The formation of superoxide radicals (O 2 •– ) was correlated with the decomposition of O 3 and the reactions of O 3 and NO 2 with antioxidants in the SLF. These radicals, in the presence of antioxidants, led to the formation of hydrogen peroxide and hydroxyl radicals ( • OH). Additionally, the direct oxidation of unsaturated lipids by O 3 and NO 2 further caused an increase in the ROS content. This change in the ROS chemistry and increased • OH production tentatively explain how inhalable oxidizing gases lead to oxidative stress and adverse health effects. In summary, our results indicated that inhaled O 3 and NO 2 exposure can significantly alter the interfacial properties of the PS, oxidize its active ingredients, and induce ROS formation in the SLF. The results of this study provide a basis for the elucidation of the potential hazards of inhaled oxidizing gas pollutants in the human respiratory system.
研究领域:
生物化学
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医学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
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IF 4.982
Zheng Lian,Lina Guo,Shule Zhang,Yongheng Xiong,Fanyu Meng,Yiqing Zeng,Qin Zhong
Excess O 3 is invariably used to ensure the effective oxidation of NO in the industrial simultaneous desulfurization and denitration through combined ozone oxidation and absorbent scrubbing. O 3 is difficult to fully react with NO considering the short residence time of flue gas , remaining O 3 transport into the subsequent absorption device, and even its escape into the atmosphere. To study the influence of excess O 3 on NO 2 absorption in sulfite solution, we simulated an integrative process of pre-oxidation and post-absorption. NO 2 removal efficiency was improved from 36.1% to 66.5% as the mole ratio of O 3 /NO increased from 1.0 to 1.6. Additionally, the effects of temperature, pH, and reactant concentration with the remaining O 3 on NO 2 removal were evaluated. After 5 h of steady absorption, the concentration of total N species in the adsorbent was 82.8 mmol/L at a O 3 /NO mole ratio = 1.6. However, this concentration was only 51.4 mmol/L at a O 3 /NO mole ratio = 1.0, indicating that more NO 2 was absorbed, and the gas-liquid transfer of NO 2 was enhanced by the excess O 3 via oxidizing NO 2 − into NO 3 − . This work contributes to re-utilizing remaining O 3 and reducing O 3 escape in simultaneous desulfurization and denitration technology.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2019
·
IF 3.45
Yunshi Liu,Xiupeng Liu,Yubing Wang,Rui Wang,Tong Zhang
A novel synthesis of In 2 O 3 porous microcolumnar structures (MCs) by a self-sacrificial template route was carried out using MIL-68. Using a modified calcination strategy, the samples could maintain the original metal organic frame work (MOF) morphology with a high gas accessibility after a slow decomposition of organic ligands. Pt nanoparticles (NPs) were loaded on the samples before or after the MOF calcination, leading to different contact states of the Pt NPs and In 2 O 3 matrix. The gas sensing properties of the samples were systematically investigated using a dynamic testing system. Particularly, sample Pt/In 2 O 3 MCs-1 exhibited a superior NO 2 sensing performance near room temperature ( R g / R a = 44.9 at 1 part-per-million and 5.2 at 100 parts-per-billion (ppb)). The sensor resistance could recover to its baseline even at 40 °C after purging with air without any additional treatment. This can be attributed to the chemical sensitisation of the Pt NPs as well as large contents of pores and channels for gas diffusion. The introduction of humidity in the gas mixture could remarkably decrease the sensor response and recovery times owing to the ‘wet’ NO 2 adsorption mechanism. This study demonstrated a novel synthesis route of Pt-loaded In 2 O 3 porous columnar structures and its potential applications in near-room-temperature detection of ppb-level NO 2 .
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2024
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IF 8
Ruilong Ma,Wenchao Gan,Yuanhu Zeng,Shuanglong Feng,Shukai Duan,Peter Feng,Xiaoyan Peng
The demand for gas sensors is experiencing rapid growth, driven by the increasing need for air quality detection in the face of environmental pollution and industrial emissions. However, the widely used metal oxide semiconductor (MOS) gas sensors suffer from drawbacks such as low ability to predict gas concentration and poor selectivity . In this work, a sensor array was fabricated consisting of 10 various gas sensors and combined with an advanced deep learning algorithm to achieve precise predictions of nitrogen dioxide (NO 2 ) at low concentrations. First, graphitic carbon nitride (g-C 3 N 4 ) and In 2 O 3 nanoparticles were composited with different mass ratios, resulting in the formation of distinct g-C 3 N 4 /In 2 O 3 composites as sensing materials. Afterward, SEM, TEM , and XRD were employed to characterize the morphology, structure, and elemental composition of the samples. Furthermore, sensing properties including response, selectivity , and repeatability, are studied for 10 gas sensors based on g-C 3 N 4 /In 2 O 3 composites. Finally, the convolutional neural network-efficient channel attention-gate recursive unit (CNN-AGRU) model was proposed to analyze the patterns of the signals collected from the sensor array when exposed to various NO 2 concentrations from 1 to 9 ppm. The results demonstrated the integration of high-selectivity sensing materials to NO 2 and an advanced deep learning algorithm CNN-AGRU enables to realize a high concentration prediction accuracy of about 97.04% and a low prediction error of 0.20527 ppm for NO 2 gas.
研究领域:
材料科学
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环境科学
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人工智能
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
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2022
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IF 6.796
Xiangyu Zang,Zhaoyan Zhang,Yingqi Zhao,Gang Li,Hua Xie,Weiqing Zhang,Guorong Wu,Xueming Yang,Ling Jiang
Elucidating the effects of anthropogenic pollutants on the photooxidation of biogenic volatile organic compounds is crucial to understanding the fundamental mechanisms of secondary organic aerosol (SOA) formation. Here, the impacts of NO 2 and SO 2 on SOA formation from the photooxidation of a representative monoterpene , β -pinene, were investigated by a number of laboratory studies. The results indicated NO 2 enhanced the SOA mass concentrations and particle number concentrations under both low and high β -pinene conditions. This could be rationalized that the increased O 3 concentrations upon the NO x photolysis was helpful for the generation of more amounts of O 3 -oxidized products, which accelerated the SOA nucleation and growth. Combing with NO 2 , the promotion of the SOA yield by SO 2 was mainly reflected in the increase of mass concentration, which might be due to the elimination of the newly formed particles by the initially formed particles. The observed low oxidation degree of SOA might be attributed to the fast growth of SOA, resulting in the uptake of less oxygenated gas-phase species onto the particle phase. The present findings have important implications for SOA formation affected by anthropogenic–biogenic interactions in the ambient atmosphere.
研究领域:
大气科学
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环境科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Shanshan Shang,Chengyan Wen,Chao Yang,Yuanmeng Tian,Chenguang Wang,Jin Shang
Nitrogen dioxide (NO 2 ) is the most toxic and prevalent form of nitrogen oxides (NO x ) pollutant and its removal from ambient air is a pressing challenge. The state-of-the-art deNO x technologies such as selective catalytic reduction (SCR) can only work at elevated temperatures (>250–300 °C), but ineffective for the NO x removal under ambient conditions. The adsorptive removal of NO 2 is an alternative approach to SCR, whose success depends on the design of stable adsorbents capable of selectively capturing NO 2 with a highly reversible capacity. Here we synthesized and developed five porphyrin-based metal-organic frameworks (PMOFs) as robust ambient NO 2 adsorbents, including three aluminum-based (Al-PMOF) isostructures, and two zirconium-based (Zr-PMOFs) isostructures. Of them, Al-PMOF stands out to be the most promising candidate by showing the highest NO 2 adsorption capacity (1.85 mmol/g), high stability, and good regenerability (retaining 87% capacity after five cycles of adsorption) at dry conditions. The NO 2 adsorption capacity of Al-PMOF was approximately doubled (3.61 mmol/g) at wet conditions. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed the NO 2 adsorption mechanism – the hydrogen bonding occurs between bridging hydroxyl (-OH) (attached to the metal node) and NO 2 molecules. Our work demonstrates that PMOFs are promising NO 2 adsorbents and will provide guidance for designing robust and reusable adsorbents for efficiently removing NO 2 at ambient temperature.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 22
·4062
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IF 5.719
Bo Zhang,Shuai Zhang,Yi Xia,Pingping Yu,Yin Xu,Yue Dong,Qufu Wei,Jing Wang
Optical excitation is widely acknowledged as one of the most effective means of balancing sensor responses and response/recovery properties at room temperature (RT, 25 °C). Moreover, noble metals have been proven to be suitable as photosensitizers for optical excitation. Localized surface plasmon resonance (LSPR) determines the liberalization of quasi-free electrons in noble metals under light irradiation, and numerous injected electrons in semiconductors will greatly promote the generation of chemisorbed oxygen, thus elevating the sensor response. In this study, pure SnO2and Au/SnO2nanowires (NWs) were successfully synthesized through the electrospinning method and validated using XRD, EDS, HRTEM, and XPS. Although a Schottky barrier led to a much higher initial resistance of the Au/SnO2composite compared with pure SnO2at RT in the dark, the photoinduced resistance of the Au/SnO2composite became lower than that of pure SnO2under UV irradiation with the same intensity, which confirmed the effect of LSPR. Furthermore, when used as sensing materials, a detailed comparison between the sensing properties of pure SnO2and Au/SnO2composite toward NO2in the dark and under UV irradiation highlighted the crucial role of the LSPR effects. In particular, the response of Au/SnO2NWs toward 5 ppm NO2could reach 65 at RT under UV irradiation, and the response/recovery time was only 82/42 s, which far exceeded those under Au modification-only or optical excitation-only. Finally, the gas-sensing mechanism corresponding to the change in sensor performance in each case was systematically proposed.Keywords:Au-loaded;UV irradiation;synergistic effect;NO2;gas sensor
研究领域:
材料科学
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纳米技术
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环境监测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
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2022
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IF 6.751
Ren Liu,Xuhao Zhu,Jian Wang,Chongxing Huang
Current methods of preserving fruit and vegetables are costly with accompanying health risks from preserver residue. ClO 2 gas preservatives can regulate the respiration and transpiration of fruit and vegetables, kill bacteria and fungi on their surface, and prolong their postharvest shelf life. Low concentration ClO 2 gas preservative will not cause safety problems and is a novel gas preservative. In this study, ethylcellulose (EC) was used as a shell material to encapsulate aqueous NaClO 2 to obtain EC-NaClO 2 microcapsules with core-shell structures. The microcapsules were inlaid in polyvinyl alcohol (PVA) film, and citric acid in the PVA film enters the microcapsules with water vapor, reacts with NaClO 2 and releases ClO 2 gas. Film-forming properties of the PVA/EC-NaClO 2 film-forming fluids were evaluated considering their viscosity and viscoelastic properties. The mechanical and gas barrier properties of the films were most suitable for the preparation of litchi storage bags when the microcapsule content was 6.0 wt%. Furthermore, the highest ClO 2 concentration in the storage bags was 263.22 ± 12.34 mg m −3 , which could kill etiological bacteria ( E. coli and L. monocytogenes ) and inhibit the growth of B. cinerea . The storage bags can extend the post-harvest shelf life of litchis and maintain their sensorial properties, such as color, moisture, hardness, weight, anthocyanins and pH. Therefore, our analysis indicates that the proposed PVA/EC-NaClO 2 active package films exhibit significant potential for applications in the field of fruit and vegetable postharvest storage .
研究领域:
食品科学
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植物学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Xiao Zhu,Liqiang Zhang,Mengze Zhang,Chunyuan Ma
Due to high adsorption capacity, NO 2 adsorption using activated carbon has become a potential denitration technology. A correlation between N-doping and NO 2 adsorption process on activated carbon is pointed out by previous studies but lacks a clear explanation. The main objective of this work is to clarify the influencing mechanism of N-doping on NO 2 adsorption and reduction over activated carbon. N-doped activated carbons were synthesized by melamine impregnation followed by calcination and tested as NO 2 adsorbents. Experimental results showed that AC600 with highest N content possessed highest NO 2 adsorption capacity and lowest NO release percentage. NO 2 adsorption on activated carbon is a complex process, including NO 2 adsorption, NO 2 reduction to NO, and NO release. Density functional theory calculations results showed that N-doping affected all steps mentioned above. Firstly, N-doping increased NO 2 physisorption energies, meaning that NO 2 was easier to be adsorbed. Thus, NO 2 adsorption capacities increased with the increase of N content experimentally. Secondly, N-doping increased the energy barrier of the rate-determining step of NO 2 reduction. Thus, the reduction of NO 2 to NO was harder. Thirdly, N-doping increased NO desorption energies, implying that the release of generated NO was harder. The inhibition of NO 2 reduction and NO desorption results in the decrease of NO release percentage due to N-doping jointly. This work elucidates the influencing mechanism of N-doping on NO 2 adsorption and NO 2 reduction on theoretical level, which fills up the research gap and guides the design of activated carbon for efficient NO 2 adsorption.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Ye Tian,Ke-Ke Wang,Gui-Peng Yang,Pei-Feng Li,Chun-Ying Liu,Riel Carlo O. Ingeniero,Hermann W. Bange
Nitric oxide (NO) is a short-lived intermediate of the oceanic nitrogen cycle, and it is produced by biological and photochemical processes in the ocean. Nitrogen dioxide (NO2) is a reactive atmospheric compound which has not been determined in the ocean so far. Here, we present the setup and validation of a novel continuous underway measurement system to measure dissolved NO and NO2 in the surface ocean. The system consists of a seawater/gas equilibration component coupled to a chemiluminescence detector. It was successfully deployed during a 12 day cruise to the East China Sea in May 2018. Dissolved NO and NO2 surface concentrations ranged from
研究领域:
海洋学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2017
·
IF 4.208
Aimin Li,Zhe Zhang,Peifeng Li,Lejuan Cai,Lizhi Zhang,Jingming Gong
Effective decomposition of perfluorooctanoic acid (PFOA) has received increasing attention in recent years because of its global occurrence and resistance to most conventional treatment processes. In this study, the complete mineralization of PFOA was achieved by the UV-photolysis of nitrate aqueous solution (UV/Nitrate), where the in-situ generated nitrogen dioxide radicals ( NO 2 ) efficiently mediated the degradation of PFOA. In particular, when the twinborn hydroxyl radicals were scavenged, the production of more NO 2 radicals realized the complete mineralization of PFOA. DFT calculations further confirm the feasibility of PFOA removal with NO 2 . Near-stoichiometric equivalents of fluoride released rather than the related intermediates were detected in solution after decomposition of PEOA, further demonstrating the complete degradation of PFOA. Possible PFOA degradation pathways were proposed on the basis of experimental results. This work offers an efficient strategy for the complete mineralization of perfluorinated chemicals, and also sheds light on the indispensable roles of nitrogen dioxide radicals for environmental pollutants removal .
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）