FUEL
·
2022
·
IF 8.035
Lei Shi,Ping Xu,Rui Wang,Weixin Tang,Tao Ding,Rongpei Jiang,Changhua Zhang
Ignition delay times of JP-10 in air and the vitiation effect of NO 2 on JP-10 autoignition at high temperatures were investigated behind reflected shock waves. The experiments were carried out at pressures of 2 and 10 atm, temperatures between 900 and 1460 K, fuel lean and stoichiometric conditions with and without 1.0 % NO 2 . The experimental results show that the ignition delay times of JP-10/air decrease with the increase of pressure or the decrease of equivalence ratio. The effect of adding 1.0 % NO 2 is pressure dependence. At 10 atm, the addition of NO 2 promotes the ignition of fuel, which shortens the ignition delay time. At 2 atm, the addition of 1.0 % NO 2 inhibits the ignition of JP-10, which prolongs the ignition delay time. A chemical kinetic mechanism of JP-10/NO 2 consisting of 290 species and 1768 reactions was developed by extending from a C0-C5 alkane and a cyclopentene sub-mechanism. The proposed mechanism has been well validated by ignition delay times, laminar flame speeds and species concentration profiles from literature. To further investigate the autoignition of JP-10 and the vitiation effect of NO 2 , kinetics analyses including reaction pathways and sensitivity coefficients were performed by the developed mechanism. The main consumption pathways of JP-10 in air are H-abstraction reactions from JP-10 by HO 2 radicals. With 1.0 % NO 2 vitiation, the addition of NO 2 has a strong effect on JP-10 consumption via the H-abstraction pathway JP-10 + NO 2 = C 10 H 15 + HONO, which further affects the autoignition of JP-10.
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高影响因子
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Junshan Hu,Fengyi Wang,Wei Jin,Changchun Ding
Upconversion nanoparticles (UCNPs) have great potential applications in biological imaging, medical treatment and optical sensing. However, the development of an inorganic-organic hybrid fluorescent probe to accurately detect noxious ions and scientifically assess irritation in vivo remains a challenge. Herein, we demonstrate a fluorescent nanoprobe for detecting nitrites (NO 2 − ) and assessing the irritation in jellyfish cell. The nanoprobe was assembled by linking neutral red to the surface of polyethylene glycol (PEG) modified NaGdF 4 :Yb,Er@NaYF 4 core/shell nanoparticles. The nanoprobe could efficiently capture the NO 2 − in jellyfish and simultaneously visualize the process. It's known that the intensity ratio of green to red emission (IRGRE) of neutral red modified upconversion nanoparticles increases linearly with the amount of NO 2 − increasing. Moreover, the irritation of NO 2 − was assessed in jellyfish cells using neutral red modified fluorescent nanoprobe based on cell imaging and spectrum signals, that NO 2 − has irrecoverable injury to the cells. This work based on dye-modified upconversion luminescence nanoprobe is expected to shed further light on the biological analysis and detection of ions.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Siyuan Lv,Yueying Zhang,Li Jiang,Lianjing Zhao,Jing Wang,Fangmeng Liu,Chenguang Wang,Xu Yan,Peng Sun,Lijun Wang,Geyu Lu
A mixed potential type yttria-stabilized zirconia (YSZ)-based NO 2 sensor attached with NiO sensing electrode (SE) with efficient three-phase boundary (TPB) processed by electrospinning technology was fabricated. The effect of the structure and area of TPB on the gas sensing performance of the sensor was investigated systematically. The YSZ nanofiber array was directly deposited on YSZ substrate by electrospinning method to construct efficient three-dimensional TPB. The sensor (S30) based on YSZ substrate processed by electrospinning method with the flow rate of 1.5 mL/h for 15 min and NiO-SE exhibited the highest sensitivity (77.4 mV/decade) to 5–500 ppm NO 2 at 510 °C, which was 2.6 times as the sensor (S00) with unprocessed YSZ substrate. The response value of S30 to 100 ppm NO 2 could reach 109 mV at 510 °C, which increased about 51 mV comparing with S00. Moreover, the sensor (S30) also displays fast response and recovery rates, good repeatability, excellent selectivity, moisture resistance and long-term stability. The elevated NO 2 sensing performance of the sensor is attributed to more active sites of electrochemical reactions by increased area of three-dimensional TPB.
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高影响因子
Engineering
·
2023
·
IF 12.8
Xiaoyu Li,Xiaoshu Lv,Jian Pan,Peng Chen,Huihui Peng,Yan Jiang,Haifeng Gong,Guangming Jiang,Li'an Hou
Photocatalysis offers a sustainable avenue for the oxidative removal of low concentrations of NO x from the atmosphere. Layered double hydroxides (LDHs) are promising candidate photocatalysts owing to their unique layered and tunable chemical structures, and the abundant hydroxide (OH − ) moieties on their surfaces that are hydroxyl radical ( • OH) precursors. However, inferior charge separation and limited active sites on an LDH hinder its practical applications. Herein, we developed a facile N 2 H 4 -driven etching (et) approach that introduces dual Ni 2+ and OH − vacancies (Ni v and OH v ) into NiFe-LDH nanosheets (referred to as NiFe-LDH-et) that facilitate improved charge-carrier separation and the formation of active Lewis acidic sites (Fe 3+ and Ni 2+ exposed at OH v ). In contrast to inert pristine LDH, NiFe-LDH-et actively removes NO when illuminated with visible light. Specifically, Ni 76 Fe 24 -LDH - et etched in 1.50 mmol·L −1 N 2 H 4 solution removes 32.8% of the NO from continuously flowing air (NO-feed concentration: ∼500 parts per billion (ppb)) when illuminated with visible light, thereby outperforming most reported catalysts. Experimental and theoretical data reveal that the dual vacancies promote the production of reactive oxygen species ( • O 2 − and • OH) and the adsorption of NO on the LDH. In-situ spectroscopy revealed that NO is preferentially adsorbed at Lewis acidic sites, particularly exposed Fe 3+ sites, and then converted into NO + that is subsequently oxidized to NO 3 − without the formation of any of the more toxic NO 2 intermediate, thereby alleviating risks associated with its production and emission.
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高影响因子
Communications Chemistry
·
2023
·Vol. 6
·期 1
·1-10
·
IF 5.9
Li Pan,Gemayel Rachel,Li Xue,Liu Jiangping,Tang Mingjin,Wang Xinming,Yang Yan,Al-Abadleh Hind A.,Gligorovski Sasho
Heterogeneous reaction of gas phase NO 2 with atmospheric humic-like substances (HULIS) is potentially an important source of volatile organic compounds (VOCs) including nitrogen (N)-containing compounds, a class of brown carbon of emerging importance. However, the role of ubiquitous water-soluble aerosol components in this multiphase chemistry, namely nitrate and iron ions, remains largely unexplored. Here, we used secondary electrospray ionization ultrahigh-resolution mass spectrometry for real-time measurements of VOCs formed during the heterogeneous reaction of gas phase NO 2 with a solution containing gallic acid (GA) as a proxy of HULIS at pH 5 relevant for moderately acidic aerosol particles. Results showed that the number of detected N-containing organic compounds largely increased from 4 during the NO 2 reaction with GA in the absence of nitrate and iron ions to 55 in the presence of nitrate and iron ions. The N-containing compounds have reduced nitrogen functional groups, namely amines, imines and imides. These results suggest that the number of N-containing compounds is significantly higher in deliquescent aerosol particles due to the influence of relatively higher ionic strength from nitrate ions and complexation/redox reactivity of iron cations compared to that in the dilute aqueous phase representative of cloud, fog, and rain water.
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PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Xiuling Zhang,Xiaoke Hao,Zhenyu Zhai,Jiaona Wang,Huiyu Li,Yaxin Sun,Yue Qin,Ben Niu,Congju Li
Wearable electronics based on metal–organic frameworks (MOFs) capable of monitoring various environmental pollutants is a promising approach for realizing gas sensing of chemical information. However, their sensing application combined with electronic textile with breathable, washable and flexible features has not been completely established yet. Herein, we describe a facile and effective strategy to fabricate flexible gas sensor for rapidly detecting hydrogen sulfide (H 2 S) through integrating NO 2 -UiO-66 on electrospun nanofibers membrane (NO 2 -UiO-66 NM) firmly and uniformly. Different from the inherent brittleness and poor processability of powder MOFs, the achieved NO 2 -UiO-66 NM delivers enhanced porosity and surface area, outstanding flexibility, desirable breathability, stable to washing and strong accessibility, more suitable for practical applications. Consequently, the fabricated NO 2 -UiO-66 NM sensor exhibits a significantly high detection selectivity for H 2 S among various analytes (H 2 S, SO 2 , C 6 H 6 , CO and NH 3 ) and remarkable sensitivity for H 2 S with unprecedentedly ultralow detection limit reaching down to 10 ppb. Moreover, the sensing performance can be greatly remained after around five weeks at concentration down to 1 ppm; also, there are slight impact of deformation on sensing activities, revealing superior H 2 S sensing stability. This study offers a feasible solution to develop electronic textiles for chemical sensing application.
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高影响因子
MOLECULES
·
2021
·Vol. 26
·期 19
·5736
·
IF 4.412
Chunhua Wang,Zhiquan Yu,Yuhao Yang,Zhichao Sun,Yao Wang,Chuan Shi,Ying-Ya Liu,Anjie Wang,Karen Leus,Pascal Van Der Voort
Upgrading furfural (FAL) to cyclopentanone (CPO) is of great importance for the synthesis of high-value chemicals and biomass utilization. The hydrogenative ring-rearrangement of FAL is catalyzed by metal-acid bifunctional catalysts. The Lewis acidity is a key factor in promoting the rearrangement of furan rings and achieving a high selectivity to CPO. In this work, highly dispersed Pd nanoparticles were successfully encapsulated into the cavities of a Zr based MOF, UiO-66-NO2, by impregnation using a double-solvent method (DSM) followed by H2reduction. The obtained Pd/UiO-66-NO2catalyst showed a significantly better catalytic performance in the aforementioned reaction than the Pd/UiO-66 catalyst due to the higher Lewis acidity of the support. Moreover, by using a thermal treatment. The Lewis acidity can be further increased through the creating of missing-linker defects. The resulting defective Pd/UiO-66-NO2exhibited the highest CPO selectivity and FAL conversion of 96.6% and 98.9%, respectively. In addition, the catalyst was able to maintain a high activity and stability after four consecutive runs. The current study not only provides an efficient catalytic reaction system for the hydrogenative ring-rearrangement of furfural to cyclopentanone but also emphasizes the importance of defect sites.Keywords:Pd/UiO-66-NO2;furfural;hydrogenative ring-rearrangement;cyclopentanone;double-solvent method
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PubMed
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.
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高影响因子
CERAMICS INTERNATIONAL
·
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 .
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Tianyi Han,Shang Gao,Ziying Wang,Teng Fei,Sen Liu,Tong Zhang
A series of reduced graphene oxide (rGO) samples were prepared by hydrothermal reduction of graphene oxide (GO) samples, which were obtained by a modified Hummers’ method at oxidation temperatures of 65 °C, 75 °C, 85 °C, and 95 °C. The combined characterizations indicate that the number of C–O bonds in rGO samples increases with an increasing oxidation temperature of GO from 65 °C to 85 °C and then decreases when the temperature is further increased to 95 °C. Most importantly, the rGO obtained from the GO at an oxidation temperature of 85 °C (designated as rGO-85) exhibits a higher response to 5 ppm NO 2 (36.7%) at room temperature than the other three rGO samples, which is attributed to the high content of C–O bonds in the rGO-85 sample. This work suggests that the gas sensing properties of rGO-based sensors can be tuned by changing the number of oxygen-containing groups in rGO.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Yujiao Zhang,Xiaoli Cheng,Xianfa Zhang,Zoltán Major,Yingming Xu,Shan Gao,Hui Zhao,Lihua Huo
Tungsten trioxide (WO 3 ) nanoparticles were synthesized via a fancil hydrothermal method with the addition of small amount of ionic liquid 1-butyl-3-methyl tetrafluoroborate ([Bmim]BF 4 ). The as-synthesized WO 3 nanoparticles were calcined at various temperatures to yield final products, which were characterized by X-ray powder diffraction meter (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Fourier transform infrared spectra (FT-IR) and N 2 adsorption-desorption methods. The sensor based on WO 3 nanoparticles that have been calcined at 500 °C for 2 h exhibits an excellent selective response to sub-ppm level NO 2 at temperatures less than 50 °C. Its resistance to humidity and stability are also good at the same condition. Besides, the detection limit for the gas sensor towards NO 2 is 100 ppb. The mechanism of NO 2 sensing was characterized and the reasons for improved NO 2 sensing performance in WO 3 nanoparticles were also proposed.
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高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2018
·
IF 3.525
Lei Chen,Ding Weng,Jiadao Wang,Duan Weng,Li Cao
The CeO 2 -TiO 2 (CeTi) and CeO 2 /WO 3 -TiO 2 (CeWTi) catalysts were prepared by a sol-gel precipitation method and their NH 3 -NO/NO 2 selective catalytic reduction (SCR) performance was studied. N 2 O formation and effect of oxygen concentration on SCR performance over CeWTi catalyst were also investigated while varying the NO 2 /NO x ratio. Results indicate that fast SCR behavior of CeWTi catalyst has the best NH 3 -NO/NO 2 SCR performance due to the catalyst reoxidation rate by NO 2 higher than by O 2 . Compared with CeTi catalyst, CeWTi catalyst exhibits higher de-NO x performance under NH 3 -NO/NO 2 SCR conditions. As the CeTi and CeWTi catalysts exhibit similar redox property, addition of WO 3 provides more acid sites which accelerate the reaction between NH 4 NO 3 and NO to get a superior low-temperature activity. Amount of N 2 O formation shows a peak at 250 °C mainly derived from NH 4 NO 3 decomposition.
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高影响因子
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