Atmosphere
·
2019
·Vol. 10
·期 2
·88
·
IF 2.046
Rui Li,Xiaotong Jiang,Xinfeng Wang,Tianshu Chen,Lin Du,Likun Xue,Xinhui Bi,Mingjin Tang,Wenxing Wang
Semivolatile organic nitrates (SVONs) contribute a large proportion of total organic nitrates and play an important role in the tropospheric chemistry. However, the composition and concentrations of SVONs in the atmosphere remain unclear due to the lack of reliable analytical techniques for specific organic nitrates. In this study, a method based on gas chromatography and electron ionization–mass spectrometry was developed to detect ambient SVONs that were collected via polyurethane foam disk enrichment. Three SVONs were identified in the semivolatile samples from urban Jinan during spring based on the characteristic fragment ions of [NO2]+and [CH2NO3]+and the characteristic fragment loss of NO2and NO3: 1-pentyl nitrate (molecular weight [MW] = 133), 4-hydroxy-isoprene nitrate (MW = 147), and (3,4)-di-hydroxy-isoprene nitrate (MW = 163). The latter two isoprene nitrates were rarely detected in the real atmosphere in previous studies. The contents of 1-pentyl nitrate, 4-hydroxy-isoprene nitrate, and (3,4)-di-hydroxy-isoprene nitrate were roughly quantified based on the standard of 1-pentyl nitrate, with a detection limit of 50 μg L−1. In addition, Fourier transform infrared spectrometry was used to determine the total SVONs content. The average concentrations of 1-pentyl nitrate, 4-hydroxy-isoprene nitrate, (3,4)-di-hydroxy-isoprene nitrate, and total SVONs in Jinan during spring were 20.2 ± 7.2, 13.2 ± 7.2, 36.5 ± 8.4, and 380.0 ± 190.8 ng m−3, respectively. The three identified SVONs contributed only 20.2 ± 5.5% to the total SVONs, which suggests that some unidentified SVONs are present in the ambient atmosphere and that studies with improved or advanced analytical techniques will be required to identify them.Keywords:organic nitrates;semivolatile sample;GC/EI-MS;identification;semiquantification
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ACS ES&T Engineering
·
2024
·
IF 7.4
Hanling Jiang,Jingwen Wang,Aijuan Zhou,Yong Liu
Advanced oxidation processes (AOPs) for removing ammonia nitrogen (NH4+-N) are of increasing interest in wastewater treatment. In this paper, the UV-activated persulfate (PS) process with CaO was applied to oxidize NH4+-N to nitrogen gas (N2). Nearly all of the NH4+-N (30 mg N/L) could be removed within 15 min, and the N2 selectivity was achieved at 95.0%. The addition of CaO made NH4+-N exist in the form of NH3, and HO• was the critical reactive species for NH4+-N oxidation. NO, N2H4, and NO2– were identified as oxidation intermediates and could be further removed. The reaction between N2H4 and NO2– with the assistance of UV/CaO promoted N2 generation during NH4+-N oxidation. The increased dosages of CaO (0.2 to 4.0 g/L) and PS (0.6 to 2.4 g/L) could enhance the NH4+-N oxidation, while the presence of CO32– (100 mM) significantly retarded the removal of NH4+-N. As high removal of NH4+-N (100%) and high N2 selectivity (>79.5%) could be achieved in lake water and secondary wastewater, the proposed UV/PS/CaO process could be potentially applied for the oxidation of NH4+-N in practical water treatment.
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JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Jiayou Liao,Zhiyuan Wu,Zhe Meng,ChengYun Gao,Jinping Li,Yong Wang,Xianjie Meng,Jiwei Ma,Lijing Yuan,Xingzhong Cao,Xu Wu
A novel methodology was proposed to simultaneously enhance both permeability and selectivity of polyimide membranes through the synergistic regulation of interchain spacing, inter-chain interactions, and functional groups, collectively referred to as 'interchain microenvironment regulation'. Through reacting the -NH 2 group on the bulky diamines with the C-Br group on the polymer chains, we successfully linked the chains by bulky diamines. The results confirmed that the introduction of bulky groups inhibited chain stacking, increased d-spacing and free volume, resulting in enhanced permeability. Moreover, the CO 2 /CH 4 selectivity was significantly enhanced due to the synergistic effect between interchain interactions and the amino groups. In particular, the PI-Br-6%-NAPD membrane demonstrated a permeability coefficient 5 times greater than that of pure PI, reaching 311.71 Barrer. And its CO 2 /CH 4 selectivity was 3.87 times higher than pure PI, with a value of 74.88. It exceeded the 2008 Robeson upper bound for gas separation performance. In addition, enhanced interchain interactions endowed the membrane with good plasticization resistance, with a plasticization pressure of up to 450 psi. Membranes modified with other diamines also exhibited excellent gas separation performance. This study provided a feasible method for effectively regulating the interchain microenvironment to achieve high-performance gas separation.
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Nature Communications
·
2025
·
IF 15.7
Yan Huihui,He Gaoxiang,Fan Rongli,Zhao Minyue,Huang Huiting,Lin Zhexing,Gao Bin,Feng Jianyong,Zou Zhigang,Li Zhaosheng
Immobilizing molecular catalysts onto gas diffusion electrodes (GDEs) through covalent bonds provides a strategy to circumvent their issues of aggregation, detachment and poor conductivity during CO 2 electrolysis. However, this approach has been limited to catalysts equipped with specially designed functional groups, and directly covalent grafting of pristine molecular catalysts onto GDEs remains a formidable challenge. Herein, using pristine cobalt phthalocyanine (CoPc) as a model catalyst, we propose a polypyrrole (ppy) mediated electro-polymerization strategy that creates robust C–C bonds between GDEs and pristine CoPc. In this scheme, ppy acts as both the conductive linker and scaffold for pristine CoPc, and its electron donation effects further enhances the CO 2 electrolysis activity of CoPc centres. Here we show that the assembled CO 2 electrolyzer using CoPc/ppy/GDE electrode achieves stable operation for 120 h at 500 mA cm −2 and 50 h at 1 A cm −2 in alkaline media. When coupled with a triple-junction solar cell, the resulting photovoltaic-electrolysis system attains a solar-to-CO efficiency of 19.2%.
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PubMed
高影响因子
Functional Materials Letters
·
2025
·
IF 1.1
Min Li,Chongcai Xu,Tianya Li,Guangyi Lin
Use trimethylethoxysilane(MTES) as hydrophobic material, graphene as conductive material, and electrospinning as preparation method to successfully prepare MTES and graphene conductive-hydrophobic composite fiber membranes. A control group was prepared based on the different doping qualities of graphene. And use the composite fiber membrane as microporous layer for proton exchange membrane fuel cell. Polarization curve test results show that with the increase of graphene, voltage loss of composite fiber membrane gradually decreases, and fuel cell performance is significantly better than that of commercial GDL29BC. Electrochemical impedance spectroscopy test results show that material transfer impedance of composite fiber membrane is lower than that of GDL29BC. It also showed that power density difference of the composite fiber membrane was low when humidity was 40% and 60%, indicating that composite fiber membrane has good self humidifying effect.
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Results in Engineering
·
2025
·
IF 7.9
Hao Sun,Guoxin Jiang,Shenghui Guo,Ming Hou,Li Yang,Xiaolei Ye,Yi Xia,Qiuni Zhao
Gas sensors based on MEMS are facing challenges such as the limited variety of micro-hot (MHP) plate structures and the low heating efficiency of MHP. This work employed COMSOL's multiphysics coupling capabilities combined with experimental validation to design and simulate a MHP structure characterized by high heat transfer efficiency, low stress, and structural stability. Based on the diverse thermal and mechanical simulation outcomes, an in-depth investigation into the influence mechanisms of MHP structural morphology, geometry, electrode patterns, and other conditions on the temperature field and thermal stress concentration within MEMS devices was conducted. This work designed and obtained the optimal device structure. At the same time, verification is conducted through experimental methods. Based on simulation results, two MHP devices were developed and manufactured using zinc oxide as the gas-sensitive material to validate their performance. Using MEMS micro-electro-mechanical systems, hydrogen gas at 500 ppm was detected at different temperatures, while their thermal and mechanical properties were simultaneously investigated. The MHP structure designed in this paper achieves the optimal operating temperature of 265°C at an extremely small voltage (0.2V), while the overall structure maintains a small deformation (<2μm). The response values of the two devices to hydrogen gas reached 6.55 and 5.47, respectively, far exceeding those of conventional planar devices. This work shows a new design method of mems chip, which can measure the concentration of hydrogen more accurately and has accurate gas sensitivity measurement ability. It plays an important role in the field of hydrogen energy safety.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Siqi Ni,Muhammad Shaban,Xuemei Ren,Changlun Chen
Radioactive iodine isotopes such as 129 I / 131 I present significant environmental and health risks due to their volatility, bioaccumulation, and long half-lives. In this study, we developed a mesoporous zirconium–porphyrin framework (Zr–TAPP) through coordination-driven self-assembly of Zr 4+ ions and tetra-aminophenyl porphyrin ligands. This material features a thermally stable two-dimensional layered structure, where π-conjugated porphyrin rings and Lewis-acidic Zr O clusters provide numerous adsorption sites. Zr–TAPP achieves high iodine vapor uptake of 1.78 g/g at 75 °C through chemisorption, reducing I₂ to I₃ − and immobilizing it via Zr N coordination and π-complexation. In aqueous solutions, it reaches a maximum iodide adsorption capacity of 303.8 mg/g at pH 7.0, driven by electrostatic attraction to protonated amino groups and porphyrin-mediated charge transfer. The adsorbent maintains 85 % of its capacity after five reuse cycles and shows strong selectivity over competing anions in aqueous solutions. Mechanistic analyses (the X-ray diffractometer and Raman spectroscopy) confirm a synergistic mechanism involving electron transfer, I₃ − formation, and hydrogen bonding at protonated nitrogen centers. This study presents a robust, efficient dual-phase iodine adsorbent that offers a promising solution for nuclear waste remediation.
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CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Zhipeng Zhu,Xiaoxue Song,Xiang Chi,Jingyao Zhao,Qiaofang Zhou,Antoni Sanchez‑Ferrer,Dengyun Tu,Wanli Cheng
Unilateral surface compression in wood presents notable benefits, including reduced wood volume loss and energy consumption, rendering a highly promising and extensive utilization. However, shortcomings in compressed wood arise due to unclear gas pressure, temperature, and moisture content distribution within the wood during hot pressing. In this paper, the temperature and pressure distribution were analyzed utilizing an optical fiber temperature and pressure measurement system within the wood during hot pressing. Moreover, the moisture content, stress and strain in each layer at the end of hot pressing were discussed extensively. The results showed that the wood surface layer (SL) and subsurface layer (SSL) maximum temperature values were similar even with different layer thicknesses. Under sealing conditions, SL and SSL temperatures were generally 6 ℃ to 7 ℃ higher compared to unsealing conditions. The gas pressure maximum value exhibited an opposite order, gradually transferring to the core layer (CL) and declining as the processing time extended. During compression treatment, moisture migrated from the hot end to the cold within the wood. The moisture content displayed significant differences between the middle and end parts of the wood under unsealed conditions, with the disparity becoming more pronounced further away from the hot end. The transition region of the compressed wood served as a stress concentration area, experiencing the highest levels of stress. The dense region followed with the second highest stress levels, while the un-densified region exhibited the least amount of stress. Under the same process parameters, the thickness had little influence on the distribution of dense layers.
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CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Zhiming Zhang,Lianzheng Gui,Zhuo Chen,Xingwu Li,Junda Quan,Sha Liang,Yibing Zuo,Jiakuan Yang,Yin Yang
Fly ash (FA) and flue gas desulfurization gypsum (FGD) are major solid wastes from coal-fired power plants, with high production and low utilization, leading to environmental pollution when stockpiled. Meanwhile, with the increase in energy consumption and the growing demand for building energy efficiency, there is an urgent need to develop safe and stable thermal insulation materials. In this study, an insulation composite material was developed using FGD building gypsum (FGDBG), combined with fly ash-based aerogel (FAA) with a low thermal conductivity of 0.0179 W/(m·K). At a FAA content of 25 wt%, the thermal conductivity of the FGDBG@FAA composite insulation material was as low as 0.080 W/(m·K), which is 83.71 % reduction compared to FGDBG without FAA, while the compressive strength and flexural strength reached 2.11 and 0.83 MPa, respectively. The heat transfer behavior of the FGDBG@FAA composites was further investigated by COMSOL software, and the results show that the FAA changed the heat transfer path and enhanced the overall thermal resistance of the FGDBG@FAA composites. By hydrophobically modifying the surface of the FGDBG@FAA composites, the softening coefficient increased from 0.34 to 0.85, which is sufficient to resist humid environments, while the thermal insulation and mechanical properties of the FGDBG@FAA composites kept stable. The evaluation of heavy metal leaching toxicity and radioactive nuclides indicates that the FGDBG@FAA composites are environmentally friendly. The composites developed in this study can be used for interior thermal insulation in buildings, enabling the co-disposal of FA and FGD gypsum while reducing environmental risks.
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Green Chemical Engineering
·
2021
·
IF 0
Qingping Xin,Xueting Cao,Dandan Huang,Shuo Li,Xinghui Zhang,Guangyu Xuan,Mengting Wei,Lei Zhang,Xiaoli Ding,Yuzhong Zhang
One type of new light-responsive hierarchical metal organic framework (MOF) has been successfully prepared using Co(NO 3 ) 3 ·6H 2 O as the metal salt and 4,4′-azobenzenedicarboxylic acid as the ligand by microwave method for the first time. It is found that MOF [Co(AzDC)] exhibits a light-responsive characteristic to SO 2 adsorption due to the presence of azo group from the ligand. The light-responsive hierarchical MOFs are incorporated into Matrimid® 5218 (PI) matrix to prepare mixed matrix membranes (MMMs) for gas separation application. The morphology, crystallinity, chain mobility and thermal stability of MMMs are explored. Results show that Co(AzDC) may elevate both the CO 2 (SO 2 ) permeability and CO 2 (SO 2 )/N 2 selectivity of the MMMs. In particular, the Co(AzDC) doped MMMs exhibit the significantly improved CO 2 (SO 2 )/N 2 selectivity from 33 (123) for PI control membrane to 78 (420) for MMMs, overcoming the 2008 Robeson upper bound for CO 2 /N 2 system. Size-sieving effect of Co(AzDC) with pore size 0.35 nm enhances the selectivity, while the –N=N– group from Co(AzDC) shows affinity to CO 2 molecular rather than N 2 , also elevating selectivity of MMMs. In brief, enhanced selectivity of high-performance membrane is attributed to incorporation of Co(AzDC) particles, which displays synergistic effects both in size-sieving and CO 2 -philic interaction for CO 2 /N 2 separation. Smart highly selective interface is constructed in MMMs by switching the configuration of MOFs from cis to trans . The SO 2 permeability and SO 2 /N 2 selectivity of MMMs are investigated under both visible light and ultraviolet light states, and the SO 2 /N 2 separation performance under visible light is notably improved in comparison with that under ultraviolet light state.
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RSC Advances
·
2022
·Vol. 12
·期 52
·33716-33724
·
IF 4.036
Jie Hu,Lei Li,Hao Li,Ying Zhai,Fushun Tang,Zhe Zhang,Banglin Chen
The mixed bimetal metal–organic framework Ni0.37Co0.63-MOF-74 has been constructed by the solvothermal method for NO adsorption. The results showed that bimetal Ni0.37Co0.63-MOF-74 takes up NO with a capacity of up to 174.3 cc g−1 under ambient conditions, which is 16.3% higher than that of the best single metal Co-MOF-74. The IAST adsorption selectivity for a NO/CO2 binary mixture can reach a maximum of 710 at low adsorption partial pressure, while the regeneration performance can be retained even after five cyclic adsorption–desorption experiments. Its separation performance was further confirmed by breakthrough experiments, indicating this new bimetal Ni0.37Co0.63-MOF-74 as one of the best materials for NO adsorption and separation in flue gas.
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COMPOSITES PART B-ENGINEERING
·
2020
·
IF 7.635
Tong Zhang,Qiancun Cheng,Bo Jiang,Yudong Huang
Gas sensors for the detection of toxic gases have attracted extensive attention due to the growing environment issue. Polysiloxane is an ideal substrate material for the flexible electronic devices. In this work, dual-activity siloxane monomer with double bonds and epoxy groups (MAGETDS) was synthesized via hydrosilylation reaction. A series of flexible polysiloxane substrate were then prepared based on the dual-activity siloxane via UV-thermal induced polymerization reaction. Besides, the regulating of reactive monomers endows the flexible polysiloxane with tunable properties. Then, polyaniline (PANI) was synthesized via a facile in-situ chemical oxidation polymerization technique and directly loaded on the polysiloxane substrate to fabricate a polyaniline/polysiloxane flexible nanocomposite film as a novel room temperature NH 3 sensor. This novel NH 3 sensors exhibited good selectivity, reproducibility and a low detection limit of 5 ppm towards NH 3 at room temperature. The strategy we developed may provide a promising approach in flexible electronics for room temperature gas sensing application.
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