ChemNanoMat
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2018
·Vol. 4
·期 5
·487-495
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IF 3.173
Zhinian Li,Shenliang Wang,Wei Hong,Shihui Zou,Liping Xiao,Jie Fan
Graphical Smart screens : An intelligent approach was developed to screen Na−Mn−W/SiO 2 catalysts for the oxidative coupling of methane (OCM). Effective composition regions other than the standard composition were successfully excavated. The wide range of the optimal composition allowed a fluctuation of composition during the reaction, which secured its excellent stability in the OCM reaction. Optimizing the performance and understanding the mechanism of metal oxide catalysts in the oxidative coupling of methane (OCM) is one of the most important projects in industrial catalysis. Here, we report an intelligent approach to screen Na−Mn−W/SiO 2 catalysts for the OCM reaction via ink-jet printing and multidimensional group testing. The ink-jet-printing-assisted (IJP-A) synthetic methodology ensured a fast synthesis of 1536 catalysts that were evaluated in 24 tests via a multidimensional group testing strategy (m-GT). After two-round synthesis-and-screening processes, several excellent groups with different composition space were screened out. Among the excellent catalysts, the OCM performance of Na−Mn−W/SiO 2 catalyst with higher Na, Mn and W content (G3 and G7) was less sensitive to its constituent than that of Na−Mn−W/SiO 2 catalyst with lower Na, Mn and W content (G1). These results indicated the sensitivity of performance to its Na, Mn and W content decreased in larger Na, Mn and W spaces, consistent with the complex homogeneous/heterogeneous reaction mechanism and multi-active sites. A series of Na−Mn−W/SiO 2 formulas with good performance also provide a reasonable explanation to its excellent stability for the OCM reaction. In addition, this intelligent optimization in total space offers a pathway to study the multicomponent metal oxide catalyst in the OCM reaction.
研究领域:
化学工程
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催化
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材料科学
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DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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2022
·
IF 4.383
Cheng Wang,Jiale Yu,Kai Feng,Huidong Guo,Lipeng Wang
In this study, natural clinoptilolite was treated with NaOH solutions of different concentrations under mild ambient conditions. The composition and structure of the as-prepared samples were characterized, and their performance was assessed in terms of the removal of the heavy metal ions Cd 2+ , Cu 2+ , and Cr 3+ from the aqueous solution. The results showed that the composition, structure, and capability of removal of heavy metal ions of the samples were significantly influenced by the NaOH concentrations. The crystal structure of clinoptilolite remained invariant under a relatively low NaOH concentration (≤0.5 M), began transforming into zeolite Na–P under a medium NaOH concentration (∼1.0 M), and then completely transformed into it under a high NaOH concentration (2.0–4.0 M). The samples treated with NaOH had lower SiO 2 /Al 2 O 3 ratios, and were superior to unmodified natural zeolite in removing the heavy metal ions. This method of treatment with relatively high concentrations of NaOH is a simple and effective way to transform natural clinoptilolite into the zeolite Na-P rich ion exchanger, which is suitable for removing heavy metal ions.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Jin Kang,Yiwu Tang,Min Wang,Chongyue Jin,Jiayun Liu,Siyan Li,Zhilin Li,Jiangwei Zhu
In this study, to enhance the peroxymonosulfate (PMS)-assisted photocatalytic degradation of tetracycline (TC) under visible light over BiVO 4 , g-C 3 N 4 coupling and Na + doping was used to co-modify BiVO 4 to obtain g-C 3 N 4 /Na-BiVO 4 (CN/Na-BiVO 4 ) heterojunction catalyst. The prepared CN/Na-BiVO 4 exhibited the apparently enhanced PMS-assisted photocatalytic TC degradation efficiency and can degrade approximately 98.20% of TC in 40 min, being 3.13 folds of BiVO 4 . The boosted TC degradation over CN/Na-BiVO 4 was ascribed to the Z-scheme heterojunction formation, doped Na + , more V 4+ and oxygen vacancies resulting from Na + doping facilitate the electron-hole pairs migration and separation. Meanwhile, more V 4+ and oxygen vacancies generated in Na-BiVO 4 also promoted the PMS activation . Therefore, a large number of reactive oxygen species (ROSs), including •O 2 − , h + , •OH, SO 4 •− , and 1 O 2 , were produced in CN/Na-BiVO 4 +PMS+Vis system to degrade TC. The mechanism of enhanced PMS-assisted photocatalytic degradation of TC was proposed. This work further highlighted the advantages of the PMS-assisted photocatalytic technology in antibiotics removal and also demonstrated that g-C 3 N 4 coupling and Na doping co-modify BiVO 4 was one effective and feasible method for promoting the PMS-assisted photocatalytic degradation of TC under visible light.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2018
·
IF 2.943
Ting Yang,Caiyun Han,Hang Liu,Liu Yang,Dekun Liu,Jie Tang,Yongming Luo
Na-X zeolite was successfully prepared from low aluminum coal fly ash (LACFA) via fusion-hydrothermal treatment. The influence of various synthesis parameters was investigated, including aluminum additives (AlCl 3 ·6H 2 O, Al(NO 3 ) 3 ·9H 2 O, AlF 3 ·3H 2 O and NaAlO 2 ), dosages of NaAlO 2 , weight ratio of LACFA/NaOH, crystallization temperature and time. The results indicated that the addition of Al species played a key role in the synthesis process of purity Na-X zeolite, and the corresponding relative crystallinity of the obtained samples was in the order of Na-X zeolite (Al) ≫ Na-X zeolite (Cl) > Na-X zeolite (N) > Na-X zeolite (F) (Here, “Al”, “Cl”, “N” and “F” represent NaAlO 2 , AlCl 3 ·6H 2 O, Al(NO 3 ) 3 ·9H 2 O and AlF 3 ·3H 2 O, respectively). And the optimal operating conditions were: the weight ratio of LACFA/NaOH = 0.83, short crystallization time 360 min, low crystallization temperature 90 °C and 0.038 mol NaAlO 2 . Additionally, X-ray fluorescence (XRF), X-ray powder diffraction (XRD), Fourier Transforms Infrared (FT-IR) and Scanning Electron Microscopy (SEM) were employed to determine the resultant samples. Based on the results of As(V) adsorption experiment, the experimental data was suitable fitted by Freundlich adsorption isotherm model, and the theoretical maximum adsorption capacity was 27.79 mg/g at pH = 2.14. The kinetics studies suggested that “surface reaction” was the rate-determining step of adsorption process, and the thermodynamics studies indicated that the adsorption process was spontaneous and endothermic. These results deemed that the LACFA was suitable for preparing Na-X zeolite (Al) , and the obtained Na-X zeolite (Al) was served as a promising adsorbent to remove As(V) from acid wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
BIOPHYSICAL JOURNAL
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2021
·
IF 4.033
Erika Aloi,Jin-Hua Guo,Rita Guzzi,Ren-Wang Jiang,Lucy Kate Ladefoged,Derek Marsh,Mikael Esmann,Rosa Bartucci,Natalya U. Fedosova
Spin labels based on cinobufagin, a specific inhibitor of the Na,K-ATPase, have proved valuable tools to characterize the binding site of cardiotonic steroids (CTSs), which also constitutes the extracellular cation pathway. Because existing literature suggests variations in the physiological responses caused by binding of different CTSs, we extended the original set of spin-labeled inhibitors to the more potent bufalin derivatives. Positioning of the spin labels within the Na,K-ATPase site was defined and visualized by molecular docking. Although the original cinobufagin labels exhibited lower affinity, continuous-wave electron paramagnetic resonance spectra of spin-labeled bufalins and cinobufagins revealed a high degree of pairwise similarity, implying that these two types of CTS bind in the same way. Further analysis of the spectral lineshapes of bound spin labels was performed with emphasis on their structure (PROXYL vs. TEMPO), as well as length and rigidity of the linkers. For comparable structures, the dynamic flexibility increased in parallel with linker length, with the longest linker placing the spin label at the entrance to the binding site. Temperature-related changes in spectral lineshapes indicate that six-membered nitroxide rings undergo boat-chair transitions, showing that the binding-site cross section can accommodate the accompanying changes in methyl-group orientation. D 2 O-electron spin echo envelope modulation in pulse-electron paramagnetic resonance measurements revealed high water accessibilities and similar polarity profiles for all bound spin labels, implying that the vestibule leading to steroid-binding site and cation-binding sites is relatively wide and water-filled.
研究领域:
生物物理学
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药理学
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DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2022
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IF 7.392
Bowen Lu,Tai Zhang,Liqi Zhang,Yongqing Xu,Zewu Zhang,Fan Wu,Xiaoshan Li,Cong Luo
CeO 2 -based catalysts have been widely used in the CO 2 hydrogenation process. The oxygen vacancies on CeO 2 resulted from Na ion incorporation play a vital role in CO 2 conversion activity, the effect of Na + ion-doped in CeO 2 during CO 2 hydrogenation was rarely studied. In this work, the LN-CeO 2 catalysts with different n NaOH :n Ce ratios were prepared with liquid nitrogen(Liquid Nitrogen-CeO 2 , LN-CeO 2 ), and the effect of the n NaOH :n Ce ratio on the microstructure of the LN-CeO 2 catalysts were evaluated. The best CO 2 hydrogenation performance was achieved by LN-CeO 2 -100 with a CO production rate of 3.90 mol/g cat· h at 800 °C (100% CO selectivity). The kinetic results indicated that the CO 2 hydrogenation performance difference among these LN-CeO 2 catalysts resulted from the CO 2 activation process. Oxygen vacancies could enhance CO 2 activation on the surface of LN-CeO 2 , and oxygen vacancies displayed a linear correlation relationship with the Na content doped in LN-CeO 2 . The highest concentration of oxygen vacancies resulted from Na ion incorporated and lower CO 2 reaction order was closely related to CO 2 hydrogenation performance of LN-CeO 2 -100. These results will give insight into the Na effect on the CO 2 hydrogenation mechanism over CeO 2 .
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 48
·17515-17524
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IF 4.099
Fengjun Chun,Binbin Zhang,Honggang Liu,Wen Deng,Wen Li,Meilin Xie,Chao Luo,Weiqing Yang
A series of Na+ and Pr3+ co-doped orange-emitting CaYAl3O7 (CYAO) phosphors were prepared by a conventional high-temperature solid-state reaction method. The crystalline structure, the luminescence properties and the decay times of the as-prepared samples were systematically investigated by X-ray diffraction (XRD) and steady-state and time-resolved photoluminescence. Under ultraviolet (UV) light and blue light excitation, the CYAO:Pr3+ phosphors exhibited orange photoluminescence emission and show potential for application in warm white LEDs, and the emission spectra of the as-prepared samples in the near-infrared (NIR) region were detected. Furthermore, Na+ ions were designed as charge compensators to maintain the charge balance. The luminescence intensities in the visible and NIR regions can be effectively enhanced by adjusting the doping amounts of Pr3+ ions and Na+ ions. Moreover, the optical spectra of Pr3+ in the CYAO host crystals were calculated by conventional parametric modeling based on the diagonalization of the complete 91 × 91 energy matrix. The calculated optical spectra were in good agreement with the observed ones and the obtained crystal field parameters were also in a reasonable range. This systemic study, and all of the above, will give a deep insight into the luminescence mechanism of the phosphors and then open one way to exploit the new phosphors for white LEDs.
研究领域:
材料科学
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发光材料
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固体化学
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光电子学
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无机功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
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2022
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IF 4.632
Lingyun Li,Ziwei Zhou,Fazheng Huang,Senlin Peng,Yantang Huang,Guoqiang Wang,Xinxu Li,Fei-Fei Chen,Chengkai Yang,Xin-Xiong Li,Yan Yu
The Er 3+ doped double perovskite Ba 2 CaWO 6 crystal is a promising ratiometric thermometer based on the fluorescence intensity ratio (FIR) of transitions from 2 H 11/2 and 4 S 3/2 to the lowered 4 I 15/2 level. However, the Ca 2+ vacancy defect caused by the charge difference between rare-earth ions and the substituted alkaline-earth ions gives rise to the non-radiative probability and limits the thermal sensitivity. Here, the up-conversion luminescence and thermometric performance of Er 3+ , Yb 3+ doped Ba 2 CaWO 6 are tuned by tri-doping with alkaline ions. The Ca 2+ vacancy defect can be eliminated by the introduction of Na + , which occupies the Ca 2+ site when it is doped into Ba 2 CaWO 6 with Er 3+ and Yb 3+ . On the contrary, the doping of Cs + into Ba 2 CaWO 6 with Er 3+ and Yb 3+ enhances the defect concentration because it occupies the site of Ba 2+ . Thus, the tri-doping of Na + reduces the non-radiative probability and enhances the quantum efficiency of Er 3+ , leading to the improvement of the thermometric sensitivity of Ba 2 CaWO 6 . As a result, we get an excellent thermometric Ba 2 CaWO 6 :8%Yb 3+ ,3.5%Er 3+ ,6%Na + powder with a luminescence lifetime of 515 μs and maximum thermal sensitivity ( S r ) of 1.45%/K, which is more than three times higher than that of the BCWO:Er 3+ powder.
研究领域:
材料科学
·
光学
·
温度测量
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产品关联
DOI
高影响因子
SOLID STATE COMMUNICATIONS
·
2023
·
IF 2.1
Zhigang Li,Yuanjie Sun,Hongtao Zhao
Lead free double perovskite nanocrystals is an ideal alternate considering its nontoxic and stable property comparing with their counterpart lead halide perovskite NCs. A simple solution synthesis strategy was used to prepare lead-free double perovskite Cs 2 AgBiBr 6 nanocrystals (NCs) doped with Na ions , resulting in NCs with a monodisperse state, homogeneous morphology, and good crystallinity . By adjusting the amount of Na + doping, the band gap of the NCs was significantly increased from 2.57 eV to 3.00 eV. Furthermore, the relatively low value of photoluminescence quantum yield (PLQY) in the original Cs 2 AgBiBr 6 NCs (∼0.5%) was increased to about 8.5% when doped with 60% Na + . Additionally, the exciton lifetime of the NCs was extended to 16.15 ns compared to the original 2 ns. As a result, the doping of Na + significantly enhanced the PLQY of Cs 2 AgBiBr 6 NCs, indicating their potential value for use in optoelectronic devices .
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2016
·
IF 2.525
Rui Ma,Jianhua Zhu,Bencheng Wu,Xiaohui Li
The commercial Na-loaded low-silica X zeolite (Na-LSX) was used as adsorbent for the removal of organic chloride compound (5-chloro-2-methylaniline) from model jet fuel. The Na-LSX adsorbent was characterized by XRD, BET, FT-IR, SEM-EDS, and XRF, respectively. A series of experiments were carried out to investigate the adsorption performance of organic chloride onto Na-LSX zeolite by batch adsorption experiments. In the batch experiments, some key operational parameters, such as temperature, adsorption time, initial concentration of organic chloride in model jet sample as well as the dosage of adsorbent were investigated. Equilibrium isotherms were analyzed by using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) adsorption models. The pseudo-first-order, the pseudo-second-order and intra-particle diffusion models were used to fit the kinetics data. The results revealed that Langmuir isotherm provided a better fit to the experimental data than other isotherms. And it was also found that the adsorption kinetics followed the pseudo-second-order kinetic equation well. The thermodynamic analysis results indicated that the adsorption process was an endothermic, feasible and spontaneous process under the specified conditions. Above mentioned investigation results implied that the Na-LSX zeolite would be an effective adsorbent for adsorption removal of organic chloride from distillate of crude oil.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Siyuan Liu,Panfu Cai,Xiaoxi Li,Ling Chen,Lin Li,Bing Li
To improve the water vapor resistance of starch-based films, Na-MMT (Na-montmorillonite) as nanofillers were fabricated into hydroxypropyl starch and the multi-scale structural changes (including intermolecular interaction, short-range conformation, long-range ordered structure and the aggregated structure of the film) were revealed. The elongation of the water vapor molecule pathway by tortuous path is generally recognized as the main reason for the improvement of water resistance. However this study observed the lowest water vapor permeability (WVP) was at the 3% Na-MMT/hydroxypropyl starch (HPS) ratio instead of 5% even nanofillers were partially exfoliated at both ratio. Except for the “tortuous path” caused by nanofillers, this observation proposed that the short-range conformation of HPS chains, long-range ordered structure and the aggregated structure likely influenced the water barrier property. The relationship between WVP and multi-scale structure of the film was investigated. The results suggested that a good balance of short-range conformationin the amorphous region, long-range ordered structure and the aggregated structure of the film was required for the improvement of water vapor barrier property.
研究领域:
材料科学
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食品科学
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产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2024
·
IF 4.8
Hao Zhou,Zhe Hong,Lijiao Ma,Yingyuan Tan,Jingcheng Xu,Wenzhi Jia,Junhui Li
The experiments of the adsorption removal of CS 2 impurity from a mimetic coke oven gas were performed by using a series of Na-type zeolites as adsorbents. Combining with the diffusion & simulation calculations and several characterizations, it's found both the development degree and the diffusion ability of microporous systems significantly influence the adsorption performance of these Na-type zeolites on which the physical absorption was predominant for CS 2 molecules. Firstly, compared with NaZSM-5 or NaSAPO-34, the NaY with FAU-type framework exhibited a much higher breakthrough adsorption capacity, primarily due to its much higher microporous surface area & volume and larger-size channels, which ensured a broader adsorption space, a high-efficiency molecule-diffusion and a high adsorption utilization of micropores. Secondly, alkali-treatment introduced some mesopores into NaZSM-5 crystals but also resulted in a declined integrity of microporous structure, causing an obvious decline of adsorption performance. Thirdly, the nano-crystal NaZSM-5 or NaY exhibited a much higher breakthrough adsorption capacity than that of the corresponding micron-crystal zeolite, primarily attributed to both the increased microporous surface area & volume and the shortened micropore diffusion-path length of the former. In addition, a breakthrough adsorption capacity of up to 0.251 g/g was obtained in the first adsorption use of a nano-NaY-0.909 sample at 298 K, and it's 0.229 g/g in even the sixteenth time of operation (by then, total adsorption service hours were 80.58 h). Our work may provide an important reference for developing high-performance adsorbents for removing gaseous CS 2 impurity in coke oven gas.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）