CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Xiaoning Liu,Junyan Fu,Yiwei Tang,Richard L. Smith Jr,Xinhua Qi
MgO-doped ordered mesoporous carbon (OMC-MgO) was synthesized by evaporation-induced self-assembly (EISA) in one-pot with biomass-derived gallic acid instead of phenolics as carbon precursor, metal ion Mg 2+ instead of formaldehyde as cross-linking agent and F127 as template. Mg had dual roles as cross-linking agent to coordinate gallic acid-F127 micelle composites, and as promoter of active sites. With the developed protocol, MgO could be uniformly dispersed throughout the carbon skeleton during calcination at 800 °C without agglomeration. As-prepared OMC-MgO-T800 had a specific surface area of 808 m 2 /g, a perfectly-ordered mesoporous structure centered at (6–8) nm, and exhibited good performance for phosphorus removal from aqueous solutions with a maximum sorption capacity of 107 mg/g. Electrostatic attraction, ligand exchange, and Lewis acid-base interactions are the main phosphate adsorption mechanisms of the developed MgO-doped OMC adsorbents. The as-prepared mesoporous carbon materials are highly selective for phosphorus adsorption from aqueous streams and are reusable and recyclable. This work proposes a green protocol to synthesize OMC-metal oxide composites that is widely applicable to wastewater treatment and technological areas in catalysis and energy storage.
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高影响因子
OPTICAL MATERIALS
·
2020
·
IF 2.779
Yanying Bi,Hang Yang,Xiaohan Yun,Hang Zhang,Xiangjie Ma,Guogang Li,Yujun Liang,Yongjun Chen
Currently, the development of highly efficient emission tunable phosphor materials is necessary for improving the lighting quality of UV light based white emitting diodes (WLEDs). Herein, a series of new blue-emitting Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ (CM/ZP: Eu 2+ ) phosphors were successfully synthesized through a high temperature solid phase reaction process. Interestingly, through constructing Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ solid solutions based on a complete substitution of Mg 2+ by Zn 2+ , the controllable blue-shift emission from 441 to 418 nm could be realized. This result could be attributed to the selective occupation of different Ca 2+ ions for Eu 2+ ions due to distortion of coordination polyhedron. The corresponding full width at half maximum (FWHM) exhibits a gradual narrowing from 66 to 27 nm after [Zn→Mg] replacement, and the color purity of Eu 2+ emission in Ca 7 Zn 2 P 6 O 24 (CZP) could reach 93.2%. Finally, the thermal quenching resistance of the as-prepared Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ phosphors show remarkably excellent performance. Moreover, the thermal stabilities working at 150 °C of CMZP: Eu 2+ were gradually improved from 71% for CZP: Eu 2+ to 97% for CMP: Eu 2+ of original photoluminescence intensity. Generally, the cation substation induced selective occupation of Eu 2+ to control FWHM is an efficient design to achieve emission-tunable phosphors, and the developed narrow-band Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ blue-emitting phosphors could serve as potential blue phosphors for WLEDs application.
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高影响因子
Catalysts
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2020
·Vol. 10
·期 5
·485
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IF 3.52
Ming Zhang,Zhen Song,Mengquan Guo,Xiangxiang Li,Yanjun Lin,Lihong Zhang
The effect of reduction atmospheres, H2/N2, C3H8/H2/N2, C3H8and CO, on the structure and propane direct dehydrogenation performance of PtIn/Mg(Al)O/ZnO catalyst derived from ZnO-supported PtIn-hydrotalcite was studied. The physicochemical properties of the as-prepared and used catalytic system were characterized by various characterization methods. The results show that the dehydrogenation performance, especially the stability of the PtIn/Mg(Al)O/ZnO catalyst, was significantly improved along with the change in reduction atmosphere. The highest catalytic activity (51% of propane conversion and 97% propylene selectivity), resistance toward coke deposition, and stability for more than 30 h were achieved with the H2/N2-reduced catalyst. The optimal dehydrogenation performance and coke resistance are mainly related to the high Pt dispersion and In0/In3+molar ratio, strong Pt–In interaction and small metal particle size, depending on the nature of the reduction atmospheres. The reconstruction of meixnerite favors the stability and coke resistance to some extent.Keywords:propane dehydrogenation;reduction atmosphere;coke deposition;meixnerite;PtIn/Mg(Al)O/ZnO
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Journal of Magnesium and Alloys
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2021
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IF 10.088
Shiquan Jiang,Zhiyuan Zhang,Dong Wang,Yuqing Wen,Ning Peng,Wei Shang
Mg alloys are considered the most promising engineering materials because of their unique properties. However, the uncontrolled corrosion rate of these alloys limits their applications. Therefore, in this study, a micro-arc oxidation layer was used as a transition layer to “directly” grow a zinc-based metal-organic framework (MOF) composite coating on the surface of a Mg alloy (AZ91D). Herein, the two zeolitic imidazolate framework (ZIF-8) coatings with different morphologies were separately prepared by homologous metal oxide induction and a one-step in-situ growth method. The superhydrophobic composite coating showed strong hydrophobicity and self-cleaning properties, which could prevent the penetration of water and corrosive ions (Cl − ) into the surface of AZ91D. Electrochemical tests demonstrated that the super-hydrophobic composite coatings greatly enhanced the corrosion resistance of AZ91D, and the corrosion current density decreased from 10 −5 to 10 −9 A/cm 2 . These results indicate that the ZIF-8 coatings are beneficial for improving the hydrophobicity and enhancing the corrosion resistance of Mg alloys. Therefore, MOF composite coatings provide a new strategy that can be used to prepare multifunctional anticorrosion coatings on metal substrates.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
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IF 3.375
Ting Li,Shuai Ma,Hu Yang,Zhen-liang Xu
Metal organic frameworks (MOFs) containing salt impurity provide a new idea for carbon material design. Presently, Mg–MOF/MgCl2 hybrid polycrystallines with different morphologies are solvothermally synthesized using 1,3,5-benzenetricarboxylic acid (BTC) or 1,4-benzenedicarboxylic acid (BDC) as the ligand, with or without polyethylene terephthalate (PET) inducer, respectively. After calcination, the products look like a flower, bud, cube, or nanosheet. When tested as adsorbent, the maximum methyl orange adsorption capacity reaches 3250 mg/g, the highest reported to date. The reason is attributed to the carbon-covered Mg salt inside the carbonized MOF. When tested as supercapacitor, carbonized MOFs based on BTC ligand show a high specific capacitance (127F/g) but a low rate capability, whereas a lower specific capacitance (121F/g) but a better rate capability (80% retention at 10A/g) are found for carbonized MOFs based on BDC. The reason is due to their different pore structures.
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高影响因子
HYDROMETALLURGY
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2019
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IF 3.465
Shuainan Ni,Caibin Wu,Yanliang Wang,Xiangguang Guo,Zeyuan Zhao,Xiaoqi Sun
Softening ammonia sulfate wastewater is one of the vital issues in the rare earth industry. In this article, a novel softening process using [4,4′-isopropylidenebis (phenoxyacetate)] (H 2 IPOAA) for Ca 2+ and Mg 2+ (M 2+ ) is developed. The effect factors, i.e., equilibrium time, pH value of aqueous phase and saponification degree are investigated. The extraction mechanism is proposed to be cation exchange. With a saponification degree of 85%, H 2 IPOAA is successfully used for the precipitation of Ca 2+ and Mg 2+ from ammonia sulfate wastewater within 10 min. The process can form precipitated particles with an average size of 35 μm, which are much larger than the precipitates formed by H 2 C 2 O 4 , Na 2 C 2 O 4 and Na 2 CO 3 . The precipitated particles can be easily separated from the raffinate. In addition, H 2 IPOAA is repeatedly used for five times with a little loss. To a considerable extent, the reuse of H 2 IPOAA contributes to lowering the cost and reducing the pollution. The concentrations of Ca 2+ and Mg 2+ in the raffinate extracted by H 2 IPOAA are up to the MVR standard for wastewater treatment . The economical and efficient softening process meets the need of green chemistry, which is expected to replace traditional industrial processes for water softening based on H 2 C 2 O 4 , Na 2 C 2 O 4 and Na 2 CO 3 .
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2018
·Vol. 94
·期 1
·167-177
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IF 2.587
Xuejuan Cao,Junnan Wei,Huai Liu,Xinyue Lv,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Shijie Liu,Lu Lin
BACKGROUND γ-Valerolactone (GVL) is a versatile biomass-derived platform molecule that could serve as a building block to produce chemicals, materials and fuels, but the production of GVL from biomass via a cost-competitive method is challenging. In this contribution, a robust Cu─Mg oxide was prepared as an efficient bifunctional catalyst for both H 2 production by MeOH reforming and hydrogenation of methyl levulinate (ML) to GVL in MeOH medium. RESULTS Cu 0.87 Mg 0.13 O x prepared by a urea hydrolysis method offered a GVL yield up to 90.6% at 220°C in 4 h without external hydrogen. This catalyst could be reused for at least seven consecutive cycles without loss of its activity. Notably, Cu 0.87 Mg 0.13 O x also provided nearly 70% GVL yield in methanolysis products of cellulose in the presence of humins. Characterization of the catalyst indicates that the incorporation of MgO greatly facilitates the stabilization of Cu + species that possess a better catalytic performance in ML hydrogenation compared with metallic Cu. CONCLUSION This robust Cu 0.87 Mg 0.13 O x could greatly contribute to develop a highly facile and desirable two-step strategy for GVL production from cellulose, through the integration of ML production by methanolysis of cellulose, H 2 formation by MeOH reforming and ML hydrogenation in MeOH medium. © 2018 Society of Chemical Industry
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Materials
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2018
·Vol. 11
·期 7
·1113
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IF 2.467
Zhe Wang,Xiaoping Shen,Temeng Qian,Kang Xu,Qingfeng Sun,Chunde Jin
The hydrophilicity and flammability of fiberboards have limited their real-life applications. In this study, a facile strategy for preparing the multifunctional coatings with superhydrophobicity and flame retardancy on medium density fiberboards (MDFs) has been investigated. The superhydrophobic and flame-retardant coating on the MDF surface was obtained by depositing polydimethylsiloxane (PDMS) and 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane (FDTS)-modified Mg/Al layered double hydroxide (LDH) particles step by step. The as-prepared coating exhibited superhydrophobic properties with a water contact angle (WCA) of ~155° and good self-cleaning properties. Furthermore, the limiting oxygen index (LOI) value of the superhydrophobic MDFs increased by 60.4% as compared to that of the pristine MDFs, showing improved flame retardancy. The peak heat release rate (PHRR) and total heat release (THR) of MDFs decreased after coating with PDMS@FDTS-Mg/Al LDH, suggesting that the superhydrophobic coating decreased the fire growth speed and risk of fire hazard of MDFs. This coating with multiple functions opens a new avenue for the protection and functionalization of MDFs.Keywords:medium density fiberboard;Mg/Al LDH;FDTS;superhydrophobicity;flame retardancy
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PubMed
高影响因子
Journal of Physical Chemistry C
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2013
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IF 4.814
Yongfeng Liu,Chao Li,Bo Li,Mingxia Gao,Hongge Pan
The hydrogen storage properties and mechanisms of the Mg(NH2)2–2LiH system with potassium halides (KF, KCl, KBr, and KI) were investigated and discussed. The results show that the KF-added sample exhibits superior hydrogen storage properties as ∼5.0 wt % of hydrogen can be reversibly stored in the 0.08KF-added sample via a two-stage reaction with an onset dehydrogenation temperature of 80 °C. However, hydrogen storage behaviors of the samples with KCl, KBr, and KI remain almost unchanged. The fact that KF can readily react with LiH to convert to KH and LiF due to the favorable thermodynamics during ball milling should be the primary reason for its significant effects, as the presence of KH provides a synergetic thermodynamic and kinetic destabilization in the hydrogen storage reaction of the Mg(NH2)2–2LiH system by declining the activation energy of the first-step dehydrogenation as a catalyst and reducing the desorption enthalpy change of the second step as a reactant. The understanding on the role played by KF sheds light on how to further decrease the operating temperature and enhance the hydrogen storage kinetics of the metal–N–H system.
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RSC Advances
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2014
·Vol. 4
·期 81
·42764-42771
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IF 3.708
Yana Liu,Jinxin Zou,Xiaoqin Zeng,Wenjiang Ding
A Mg–Ti nano-composite has been co-precipitated from a tetrahydrofuran (THF) solution containing anhydrous magnesium chloride (MgCl2), titanium tetrachloride (TiCl4) and lithium naphthalide (LiNp) as the reducing agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and pressure-composition-temperature (PCT) techniques are used to characterize phase components, microstructure and hydrogen sorption properties of the composite. The co-precipitated Mg–Ti nano-composite contains nearly 1.0 wt% of Ti distributed homogeneously on the surface or inside Mg particles having an average particle size of about 50 nm. Orthorhombic γ-MgH2 phases and tetragonal γ-TiH2 phases are obtained when the Mg–Ti nano-composite is hydrogenated at 75 °C. PCT measurements reveal the superior hydrogen absorption property of the Mg–Ti nano-composite: its maximum hydrogen capacity can reach up to 6.2 wt% within 2 h at room temperature under a hydrogen pressure of 3 MPa. The activation energy for hydrogen absorption is determined to be 50.2 kJ mol−1 H2. The hydrogenation and dehydrogenation enthalpies of the nano-composite are calculated to be −73.0 ± 1.8 and 75.8 ± 4.7 kJ mol−1 H2, close to the standard values for Mg (−74.1 ± 2.9 kJ mol−1 H2). The catalytic effects from the co-precipitated Ti and the tetragonal γ-TiH2 formed during the hydrogenation process lead to extremely fast absorption kinetics at room temperature.
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高影响因子
MATERIALS LETTERS
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2015
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IF 2.489
Xiwei Liu,Jianke Sun,Yinghong Yang,Feiyu Zhou,Zhongjie Pu,Li Li,Yufeng Zheng
The microstructure, mechanical properties , in vitro degradation behavior and hemocompatibility of novel Zn–1Mg–0.1Sr and Zn–1Mg–0.5Sr (wt%) ternary alloys were evaluated with pure Zn as control. The results indicated that Zn–Mg–Sr alloys exhibited much higher yield strength (YS), ultimate tensile strength (UTS), hardness and corrosion rate than those of pure Zn. But their elongation and hemolysis rates were reduced. Furthermore, the hot-rolled Zn–1Mg–0.1Sr alloy presented the superior mechanics performance (196.84±13.20 MPa, 300.08±6.09 MPa, 22.49±2.52%, 104.31±10.18 for YS, UTS, Elongation and hardness, respectively), appropriate corrosion rate (0.15±0.05 mm/year) and excellent hemocompatibility (hematolysis rate of 1.10±0.2% and no signs of thrombogenicity), showing a preferable candidate as the biodegradable implant material .
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2017
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IF 3.133
Li-Feng Zhu,Bo-Ping Zhang,Shun Li,Gao-Lei Zhao
The (1- x )Bi 1+ y (Fe 0.96 Mg 0.02 Ti 0.02 )O 3 - x BaTiO 3 (abbreviated as B 1+ y FMT- x BT) system was designed to explore the morphotropic phase boundary (MPB) separating rhombohedral ( R ) and tetragonal ( T ) phases, and the mechanism of performance enhancement. The phase structure of samples was discreetly investigated by X-ray diffraction, and Rietveld refinement results of the XRD data revealed that the B 1+ y FMT- x BT ceramics consist of an R phase at x = 0.24, two R and T phases at 0.26 ≤ x ≤ 0.32, and a single T phase at x = 0.34. Because of the MPB and the improvement of resistivity with adding excess Bi compensation, excellent piezoelectric properties of d 33 = 198 pC/N and k p = 30.9%, as well as high Curie temperature T C = 497 °C were achieved in the B 1+ y FMT- x BT system at x = 0.30 and y = 0.02. Here, the large d 33 = 198 pC/N which is the maximum value for the BF-BT-Bi(Mg,Ti)O 3 system so far, and high T C = 497 °C suggest that Bi(Fe,Mg,Ti)O 3 -BaTiO 3 ceramics have good prospects in high-temperature piezoelectric devices.
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