Materials Research Express
·
2019
·Vol. 6
·期 11
·115504
·
IF 1.449
Peng Wang,Qi Sun,Yujiao Zhang,Jun Cao
The zeolite NaA was successfully synthesized by hydrothermal method using kaolin as a raw material. In order to study the crystallization mechanism, the products and intermediates of different crystallization stages were systematically characterized using x-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM)-energy-dispersive spectrometry (EDS). The results show that the metakaolin is completely dissolved during the first hour of the crystallization process, forming a rich crystal nucleus. As the crystallization time increases, the nucleus grows rapidly to form zeolite NaA crystals. When the crystallization time reaches 3 h, the percentage crystallinity of zeolite NaA reaches a maximum. Therefore, it can be concluded that the optimum crystallization time of zeolite NaA is 3 h. Meanwhile, we can come to the conclusion that the synthesis of zeolite NaA from kaolin is a liquid phase transition mechanism. The microstructure of zeolite NaA synthesized at 3 h of crystallization was further investigated by transmission electron microscopy (TEM) technique. The SAED patterns indicate the polycrystallinity of the zeolite NaA structure. The electron diffraction pattern indicates that the crystal structure type of the zeolite NaA belongs to the body center cube (BCC). The textural properties of the zeolite NaA synthesized at 3 h of crystallization were studied by nitrogen adsorption technique. It can be concluded that the BET surface area of the zeolite NaA obtained by the BET method is 21.106 m2·g−1. Meanwhile, from the BJH method, it is found that the microporous surface area and micropore volume of the zeolite NaA are 13.929 m2·g−1 and 0.052 cm3·g−1, respectively.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Yijie Wang,Zhixin Chen,Liming Hu
Specific surface area is an important property of porous materials and a crucial index in multiple disciplines, which is mainly measured using nitrogen isotherms and the Brunauer–Emmett-Teller (BET) equation. The BET surface area is remarkably higher than the geometric surface area, which is defined as the surface area of the crystal geometry structure. However, many studies directly use the BET surface area as the geometric surface area. We proposed a simple, general, and accurate method that only needs the nitrogen adsorption isotherm as the input to calculate the geometric surface area of mesoporous materials. The proposed method considers the adsorptive potential influences and the physical state of adsorbed nitrogen in estimating the surface area. We utilized 18 isotherms generated by molecular simulations and actual experiments to cover a wide range of materials, including minerals, catalysts, and carbon-based tubes, and validate the effectiveness of the proposed method. Our results showed that the surface area determined by the proposed method is almost identical to the referenced geometric area. The surface area obtained by the proposed method can be typically considered a geometric surface area.
研究领域:
材料科学
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物理化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Hafezeh Nabipour,Yuan Hu,Sohrab Rohani
A novel complex, resulting from the synthesis of a guanazole ligand coordinated with Zn(II), has been successfully synthesized through an environmentally friendly method and carefully characterized using a combination of analytical techniques, including Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), N 2 adsorption–desorption, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The Brunauer–Emmett–Teller surface (BET) surface area of the guanazole complex is determined to be approximately 407.50 m 2 /g, featuring pore diameters and pore volume of 1.84 nm and 0.187 cm 3 /g, respectively. The emergence of micropores in the guanazole complex significantly enhances its CO 2 adsorption capacity. The maximum CO 2 adsorption capacity of the complex is observed to be 3.18, 2.08, and 1.51 mmol/g at temperatures of 273, 298, and 313 K, respectively. This study presents novel prospects for the controlled synthesis of nitrogen-rich complexes and their potential application in CO 2 capture.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 33
·5595-5600
·
IF 3.545
Ji Ping Zhu,Xue Feng Wu,Xiao Hua Yang,Peng Fei Liu,Sheng Dai,Hua Gui Yang
Mesoporous single crystals have attracted considerable attention owing to their wide applications in (photo)catalysis, photovoltaics, and numerous other electrical energy conversion and storage technologies. Here, by using low-valent Ti3+ precursors, we have successfully synthesized well-defined mesoporous single-crystal strontium titanate (MSC SrTiO3) without a template via a facile hydrothermal method. The BET surface area and average pore diameter of MSC SrTiO3 are 18.6 m2 g−1 and 22 nm, respectively. Moreover, the as-synthesized MSC SrTiO3 features abundant oxygen vacancies. By using time-dependent structural and morphological characterizations, a hypothetical crystal growth mechanism was proposed.
研究领域:
材料科学
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纳米技术
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催化
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光伏
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电能转换与存储
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chengxin Zhang,Lulu Yang,Lin Zhao,Yu Liu,Dongfeng Hong,Xiaoyuan Shi,Shaolei Wang,Guangshan Zhu
Various porous adsorbent materials have shown excellent adsorption performance for the removal of organic micro-pollutants in water. However, the practical application was hindered by the high cost or slow adsorption kinetics for most of porous adsorbents. Therefore, it is of great significance to develop economic adsorbent materials with characteristic like low-cost, easier preparation method, excellent adsorption kinetics etc . Herein, based on the Friedel-Crafts alkylation reaction, we reported three novel hydrophilic organic porous adsorbent frameworks (PAF-210, PAF-211 and PAF-212) with high Brunauer-Emmet-Teller (BET) surface area (956 ∼ 1384 m 2 /g) for phenolic micro-pollutants (bisphenol A (BPA), 2,4-dichlorophenol (2,4-DCP) and 2-naphthol (2-NO)) adsorption in water, which were prepared by using cheap trimethyl orthoformate (TMOF) as crosslinker and one-step simple ball milling synthetic method under room temperature within 15 min. Rich oxygen content promotes the resulting polymers to possess excellent hydrophilicity and wettability through water vapor adsorption and water contact angle analysis. The excellent hydrophilicity and proper porous properties made the resulting frameworks suitable as porous organic adsorbents to rapidly remove organic phenolic micro-pollutants from water. Among the resulting polymers, the PAF-210 exhibited ultra-fast adsorption (>94.0 % within 5 s), ultra-rapid adsorption kinetics with pseudo-second-order rate constants (K 2 , up to 7.72g/mg min −1 for 2,4-DCP), high pollutant adsorption capacity (up to 867.03 mg g −1 for BPA) and excellent recyclability (10 cycles with slight loss in adsorption capacity) through systematically characterization. The adsorption performances of PAF-210 are much better than these of the commercial activated carbons and β-cyclodextrin-based porous adsorbents (K 2 = 1.50g/mg min −1 for P-CDP) etc . The favorable hydrophilicity, surface wettability, and adsorption performance of PAF-210 were significantly better than the comparative material constructed by using benzene and formaldehyde dimethyl acetal (FDA) through conventional thermal synthetic method, which is a very classic synthesis strategy in the field of porous materials. More importantly, the PAF-210 exhibited relatively superior adsorption performance on BPA, and it still presented excellent adsorption performance (removal efficiency ≥ 96.8 % within 5 s after 10 cycles) even at the safe range of BPA quantified in drinking water (BPA≤10 μg L −1 , Standards for drinking water quality, GB5749-2022, China). XPS analysis and theoretical simulations proved that the excellent adsorption performance and ultra-fast adsorption rate stem from interactions including π-π interactions, hydrogen bonding and van der Waals interactions between PAF-210 and micro-pollutants.
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
Nanomaterials
·
2022
·Vol. 12
·期 4
·668
·
IF 5.719
Qingyun Li,Lingyu Liu,Zihua Wang,Xuezhong Wang
A confined jet mixing reactor operated in continuous hydrothermal flow synthesis was investigated for the synthesis of CeO2-ZrO2(CZ) nanoparticles. The obtained ultrafine powders were characterized using scanning electron microscopy–energy dispersive spectrometry (SEM-EDS), inductively coupled plasma–atomic emission spectroscopy (ICP-AES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED), a BET (Brunauer-Emmett-Teller)-specific surface area test and pore analysis, oxygen storage capacity (OSC) test, and a H2temperature programmed reduction (H2-TPR) test. The XRD results show that all samples were composed of high-purity cubic CZ nanoparticles. High resolution transmission electron microscope (HR-TEM) analysis showed that CZ nanoparticles with uniform size and shape distributions were obtained in this investigation. The d-spacing values, determined based on the TEM-selected area electron diffraction (SAED) patterns, were in good agreements with the reference data. BET results showed that the prepared CZ samples had large specific surface areas. Pore volume and size distribution were obtained by pore analysis. Oxygen pulse adsorption technology was used to test the oxygen storage capacity of the sample. The redox capacity of the CZ material was determined by a H2temperature-programmed reduction test.Keywords:continuous hydrothermal flow synthesis;confined jet mixing reactor;CeO2-ZrO2nanoparticles;XRD;BET
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2018
·Vol. 2018
·期 8
·1047-1052
·
IF 2.507
Xiaoxia Jia,Ning Yuan,Li Wang,Jiangfeng Yang,Jinping Li
Graphical Both high selectivity and adsorption capacity in the adsorptive separation of CO 2 , CH 4 , and N 2 were achieved by means of (CH 3 ) 2 NH functionalization of the unsaturated metal sites of the MOF Ni-HKUST-1. Ni-HKUST-1, with the same topological structure as Cu-BTC (HKUST-1), was synthesized by a (CH 3 ) 2 NH-assisted method. Ni-HKUST-1 with high purity (> 90 %), yield (85 %), and BET surface area (1088 m 2 /g) was successfully synthesized for the first time by using NiCl 2 . The pure-component adsorption isotherms of CO 2 , CH 4 , and N 2 on Ni-HKUST-1 were measured by the volumetric method and the data used to estimate the separation selectivity for CO 2 /CH 4 , CH 4 /N 2 , and CO 2 /N 2 binary mixtures according to the ideal adsorbed solutions theory. At 273 K and 1 atm, the selectivities for CO 2 /CH 4 , CH 4 /N 2 , and CO 2 /N 2 were 14.49, 5.36, and 183.41, respectively, and the adsorption capacities for CO 2 and CH 4 were 223.87 and 67.89 cm 3 /g, respectively. This is a rare demonstration of both high selectivity and adsorption capacity in the separation of CO 2 , CH 4 , and N 2 .
研究领域:
材料科学
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化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2022
·
IF 2.042
Jun Cao,Qi Sun,Peng Wang,Jie Shen,Xue Dai
In order to solve the problem that separating zeolite 4A from solutions, we have synthesized Fe3O4/zeolite 4A magnetic nanocomposite by hydrothermal method. It is characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), Vibrating Sample Magnetometer (VSM), scanning electron microscope (SEM) and Brunner-Emmet-teller (BET). The XRD result shows that Fe3O4/zeolite 4A magnetic nanocomposite has a good crystal structure. It also shows that Fe3O4/zeolite 4A magnetic nanocomposite contains two phases of zeolite 4A and Fe3O4 MNP. The optimal sample (Z-2) was judged by the calculation of crystallinity. The successful combination of zeolite 4A and Fe3O4 MNP was visually observed through SEM technology. The functional groups of Fe3O4/zeolite 4A magnetic nanocomposite were characterized by FTIR technology. The TEM result shows that some Fe3O4 MNPs enter zeolite 4A, which further clarifies the microstructure of Fe3O4/zeolite 4A magnetic nanocomposite. N2 adsorption-desorption technique confirms that Fe3O4/zeolite 4A magnetic nanocomposite SBET is 55.3374 m2/g and Dave is 9.7128 nm. VSM result shows that Fe3O4/zeolite 4A magnetic nanocomposite magnetization is 18.4534 emu/g. Simulation experiment shows that Fe3O4/zeolite 4A magnetic nanocomposite exhibit a fast response to an external magnetic field.
研究领域:
材料科学
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纳米技术
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化学工程
·
磁性材料
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产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2014
·Vol. 73
·期 1
·270-277
·
IF 1.547
Liu Panxing,Xie Shuangfei,Peng Muyang,Ni Liang,Tang Yuefeng,Chen Yanfeng
Abstract Hollow SiO 2 nanospheres were fabricated by a modified Stöber method. Hollow Si–SiC composite nanospheres were firstly prepared by reducing the hollow SiO 2 nanospheres by a low temperature magnesiothermic reduction method. In the final samples of hollow Si–SiC composite nanospheres, the hollow nanosphere structure of the precursor was well preserved. SiO 2 nanospheres and Si–SiC composite nanospheres with hollow structure were observed by Scanning electron microscopy and Transmission electron microscopy. Nitrogen absorption–desorption measurement indicated that Si–SiC composite nanospheres had large BET surface area of 150.33 m 2 /g and pores about 12.9 nm, and the hollow structure was indirectly confirmed. X-ray diffraction, X-ray photoelectron spectroscopy, and TG-DSC were also carried out to characterize microstructure and composition of the final samples. Graphical Abstract
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
APPLIED CLAY SCIENCE
·
2019
·
IF 3.89
Haiyan Yang,Yang Zhou,Dongshen Tong,Miao Yang,Kai Fang,Chunhui Zhou,Weihua Yu
Cellulose is the most abundant form of biomass on earth, and is considered as an alternative for fuels and chemicals. The hydrolysis of cellulose to platform compounds, such as reducing sugars (RS), is one of the most important ways for the utilization of cellulose. In this study, the solid acid catalysts of SO 4 2− -ZrO 2 /montmorillonite (SZ-Mt) were prepared by coupling SO 4 2− with ZrO 2 and then introducing into the interlayer of Mt using the coprecipitation method. Meanwhile, the catalytic performance of the SZ-Mt catalysts for the hydrolysis of cellulose to RS in water was studied. The catalysts were characterized by XRD , FT-IR, BET, SEM(EDS), NH 3 -TPD and XPS . The catalytic results showed that the SZ-Mt composite calcined at 500 °C with the molar ratio of S/Zr of 0.3 showed the highest total reducing sugars yield of 30.1%. The characterization results revealed that the surface S O bonds of sulfated zirconium oxide could gradually change from O=S-OH groups (type I, -HSO 4 ) to O=S=O groups (type II, -S 2 O 7 ). It was concluded that the surface S-OH groups in type I were responsible for the hydrolysis of cellulose in the low molar ratio of S/Zr and the new S-OH bonds formed by breaking the S-O-S bonds in type II were contributed to the conversion of cellulose in the high molar ratio of S/Zr. Finally, the mechanism of cellulose hydrolysis on the SZ composites was suggested.
研究领域:
化学工程
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材料科学
·
生物化学
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2022
·Vol. 153
·期 3
·921-930
·
IF 2.936
Zhang Kai,Zhang Huanling,Feng Xipan,Wang Yue,Wang Guowei,Zhu Xiaolin,Li Chunyi
The catalytic activities of metal–based catalysts are largely dependent on the properties of their supports. The support (MgO, Al 2 O 3 , MgAl 2 O 4 , SiO 2, and CeO 2 ) effect of the Sn (1.2 wt%) based catalyst for the ethylbenzene dehydrogenation reaction was firstly investigated. The supported Sn-based catalysts were characterized by NH 3 -TPD, BET, XRD, and H 2 -TPR. Among the tested catalysts, the 1.2 Sn/CeO 2 catalyst presented the most effective catalytic activity, achieving a high ethylbenzene conversion of 56.2 wt% at 600 °C. The obvious support effect should originate from the electronic interaction between Sn and supports, instead of the geometric effect resulting from different dispersion of Sn species on carriers. The high activity of the 1.2 Sn/CeO 2 catalyst was attributed to the generation of oxygen vacancies on the CeO 2 surface. A typical strong metal-support interaction (SMSI) could be found in the 1.2 Sn/CeO 2 catalyst according to the comparison of H 2 -TPR, XPS, and Raman spectra result with pure CeO 2 support. The addition of Sn further promoted the generation of more oxygen vacancies by changing the redox properties of CeO 2 , and inhibited the agglomeration of CeO 2 nanoparticles, thereby enhancing greatly the catalyst's ethylbenzene dehydrogenation activity. Graphical Abstract
研究领域:
催化
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化学工程
·
材料科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 14
·22073-22086
·
IF 0
Wang Youqun,Cai Weiqian,Xiong Lingshan,Pei Jiaying,Zhang Zhibin,Xu Lin,Liu Yunhai,Cao Xiaohong
Inspired by its large specific surface area, and tunable chemical and physical properties, a hollow carbon-based mater8ial derived from ZIF-8 with phosphate groups (HCM-PO 4 ) was prepared for the elimination of U(VI). The structural and surface features of HCM and HCM-PO 4 were thoroughly examined using techniques such as SEM, TEM, and XRD. The resulting carbon material, HCM-PO 4 , exhibits a higher BET surface area of 571.2 m 2 ·g -1 , featuring a hollow structure. The removal procedure of HCM-PO 4 for U(VI) aligns with the quasi-secondary kinetic model. Furthermore, the theoretical sorption capacity of HCM-PO 4 was found to be 482.30 mg·g -1 at 298.15 K. The results obtained from XPS, FT-IR, and EDS analysis of HCM-PO 4 after adsorption revealed the coordination of the phosphate group for U(VI), contributing significantly to the adsorption process. In brief, the HCM-PO 4 demonstrates excellent adsorptive ability, positioning it as a hopeful expectant to remove U(VI) from wastewater.
研究领域:
环境科学
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材料科学
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核废物处理
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吸附技术
✓ 已验证
DOI
危险品化学品经营许可证（带存储）