The rational design and precise synthesis of multifunctional hybrid nanostructures with a tailored active core and a large, dendritic, modified mesoporous structured shell can promote catalysis, energy storage, and bi...The rational design and precise synthesis of multifunctional hybrid nanostructures with a tailored active core and a large, dendritic, modified mesoporous structured shell can promote catalysis, energy storage, and biological applications. Here, an oil-water biphase stratification coating strategy has been developed to prepare monodisperse magnetic dendritic mesoporous silica core-shell structured nano- spheres. These sophisticated Fe3O4@SiO2@dendritic-mSiO2 nanospheres feature large dendritic open pores （2.7 and 10.3 nm）. Significantly, the silica shells can be converted into dendritic mesoporous aluminosilicate frameworks with unchanged porosity, a Si/Al molar ratio of 14, and remarkably strong acidic sites, through a post-synthesis approach. In addition, the resultant magnetic dendritic mesoporous aluminosilicate nanospheres exhibit outstanding properties and promising application in phosphate removal from wastewater.展开更多
The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses （x = 0 to 7 mol%） are investigated. Both Raman and IR spectra reveal that discrete phosphate species （[PO4]-3, [PO3O1/2]-2） with low pol...The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses （x = 0 to 7 mol%） are investigated. Both Raman and IR spectra reveal that discrete phosphate species （[PO4]-3, [PO3O1/2]-2） with low polymerization degree can be formed in the silicate glass. These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network, resulting in an increase of the glass transi- tion temperature. According to the Judd-Ofelt intensity parameters （Ω2,Ω4, Ω6） of Er3＋, the asymmetry of local environment around Er3＋ becomes higher, and the bond covalency between Er3＋ and O2-decreases after P2O5 is introduced. In the emission spectra, photoluminescence intensity increases with increasing P2O5 concentration and the spectra are inhomogeneously broadened, revealing that the ligand electric field around Er3＋ is dramatically changed, and the glass matrix becomes disordered.展开更多
Well-ordered aluminosilicates(MAs)were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale,and applied in an industrial fluid catalytic cracking unit for the first time...Well-ordered aluminosilicates(MAs)were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale,and applied in an industrial fluid catalytic cracking unit for the first time.Compared with incumbent equilibrium catalyst,the surface area of trial equilibrium catalysts(30%inventory ratio)increased from 110 m^(2)g^(-1)to 120m^(2)g^(-1).Moreover,a significant increase of the mesoporous surfaceareaof trial equlibrium catalysts(30%inventoryrati)from 33 m g/to 40magi(22%increase).Furthermore,the equilibrium catalyst that contain 80%LPC-65 yields significantly lower heavy oil(0.23%)and higher total liquids(0.53%)compared with LDO-70.The industrial results demonstrated excellent hydrothermal stability and superior catalytic cracking properties,showing the promising futurein the industrial units.展开更多
The effects of bismuth doping content and temperature on the absorption property and near-infrared （NIR） luminescence of Bi-doped La2O3-Al2O3-SiO2 （LAS） glasses are presented. The emission intensity reaches the ma...The effects of bismuth doping content and temperature on the absorption property and near-infrared （NIR） luminescence of Bi-doped La2O3-Al2O3-SiO2 （LAS） glasses are presented. The emission intensity reaches the maximum when the Bi2O3 content in 3.0Bi-LAS is 1.83%. The emission spectra reach their peaks at 1 190 and 1 117 nm, with full-width at half-maximum （FWHM） values of 330 and 228 nm under 500 and 700-nm excitations, respectively. As the Bi203 content increases, the peak wavelengths and FWHMs of emission bands increase, but their lifetimes decrease. The lifetime of 2.0Bi-LAS is 460 μs at 9 K, and is almost temperature independent until 350 K. The NIR emission of Bi in the system has strong resistance to thermal quenching from 9 to 350 K.展开更多
A unique templating approach for the synthesis of hexagonal mesoporous aluminosilicates via self assembly of pre formed aluminosilcate nanoclusters with the templating micella formed by cetyltrimethylammonium bromid...A unique templating approach for the synthesis of hexagonal mesoporous aluminosilicates via self assembly of pre formed aluminosilcate nanoclusters with the templating micella formed by cetyltrimethylammonium bromide (CTAB) is described. The obtained materials of MAS 5 are hydrothermally stable, which is shown by X ray diffraction (XRD) analysis. Furthermore, as characterized by NMR technique, MAS 5 has stable tetrahedral aluminum sites that is the major contributions to the acidity of aluminosilicate molecular sieve, and on non framework aluminium species in the samples was observed.展开更多
In this study the characterization of an aluminosilicate synthesized from commercial Al2(SO4)3 and colloidal SiO2 is presented, as well as its capacity for the removal of copper from aqueous solution. Characterization...In this study the characterization of an aluminosilicate synthesized from commercial Al2(SO4)3 and colloidal SiO2 is presented, as well as its capacity for the removal of copper from aqueous solution. Characterization of the synthesized material was performed using X-ray diffraction, BET nitrogen adsorption-desorption, mass titration and the Boehm method. In order to obtain stable agglomeration and enhance its surface area (165 - 243 m2/g) and solid adsorbing capabilities, the molar ratio SiO2:Al2O3 (1:3, 1:1 and 3:1) was studied, the solubility of the preparation material, synthesis-procedure time and solution pH function were also examined. The maximum capacity to remove copper ions from an aqueous solution by synthesized aluminosilicate was 16 mg/g at pH 4 and 25℃. The Langmuir model fitted better to the copper adsorption experimental data.展开更多
Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was s...Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MAS>MCM-41>NaY. The improvement of desulfurization ability of MAS by Cu+ is more significant than that of Ag+.展开更多
Low-cost adsorbents constituted by Fe-modified-aluminosilicates （laminar and zeolite type minerals） were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried o...Low-cost adsorbents constituted by Fe-modified-aluminosilicates （laminar and zeolite type minerals） were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried out ＂in situ＂ by the synthesis and deposition of mesoporous ferrihydrite. Natural iron-rich aluminosilicate was used as reference. All samples were characterized by X-ray diffraction, Raman spectroscopy, BET N2-adsorption, SEM-EDS microscopy and ICP chemical analysis. Experimental results of arsenic sorption showed that iron-poor raw materials were not active, unlike iron activated samples. The iron loading in all activated samples was below 5% （expressed as Fe203）, whereas the removal capacity of these samples reaches between 200-700 gg of As by g of adsorbent, after reusing between 17 cycles and 70 cycles up to adsorbent saturation. Differences can be associated to mineral structure and to the surface charge modification by iron deposition, affecting the attraction of the As-oxoanion. On the basis of low-cost raw materials, the easy chemical process for activation shows that these materials are potentially attractive for As（V） removal. Likewise, the activation of clay minerals, with natural high content of iron, seems to be a good strategy to enhance the arsenic adsorption ability and consequently the useful life of the adsorbent.展开更多
Cementitious alkali activated aluminosilicates pastes were produced from recycled and locally obtainable materials in Iraq. The compositions were based on recycled bricks, water glass, commercial caustic soda flakes, ...Cementitious alkali activated aluminosilicates pastes were produced from recycled and locally obtainable materials in Iraq. The compositions were based on recycled bricks, water glass, commercial caustic soda flakes, and nano silica. The nano silica was prepared from the abundant local ＂Iraqi anber＂ rice husks and added to the prepared pastes in different weight percentages. Another set of pastes was prepared via adding 5w% of＂A1-Najaf＇ fly ash at the expense of the recycled bricks powders. The pastes were cured for 1-28 days under ambient conditions. The compressive strengths for the cured pastes were measured. In addition, the cured pastes were characterized via X-ray diffraction, FTIR, and optical microscopy. The addition of the nano silica and longer curing times improve the microstructure packing and thus increases the compressive strengths. The added fly ash impregnates the microstructure with extra gel phase and further improves the compressive strengths of the cured pastes.展开更多
Manganese is ubiquitous in terrestrial environments and most studies have focused on dissolution of Mn oxides,but aluminosilicates also release Mn.Here,we evaluated oxic Mn dissolution from six rocks and minerals(amph...Manganese is ubiquitous in terrestrial environments and most studies have focused on dissolution of Mn oxides,but aluminosilicates also release Mn.Here,we evaluated oxic Mn dissolution from six rocks and minerals(amphibolite,anorthosite,kaolinite,kyanite,muscovite,orthoclase feldspar) and soils from four Critical Zone Observatories(CZOs) under four LMWOLs treatments(catechol,citric acid,oxalic acid,control).Overall rock and mineral Mn mass-normalized release was 1.4 ± 0.5 nM μM^(-1) 14 d^(-1) and dissolution rate was 2403 ± 935 nM m^(-2) d^(-1) x 10^(3).Overall CZO soil Mn release was 16.7±5.1 nM μM^(-1) 14 d^(-1) and dissolution rate was 7010 ± 2570 nM m^(-2) d^(-1) × 10^(3).Anorthosite and kyanite had the highest Mn dissolution rates but kaolinite and kyanite had the highest Mn mass-normalized release rates.We hypothesize the structural location of Mn,surface area,and potential inclusions of highly-weatherable-phases control Mn dissolution for rocks and minerals.CZO soils with the highest solid phase Mn had the highest Mn release and dissolution rates.Citric acid and catechol had higher Mn release and dissolution rates than the control while oxalic acid did not.For rocks and minerals,we found pH 4 had higher Mn release and dissolution rates than pH6,but not for control treatments without LMWOL.Our study highlights that the abundance of Mn drove Mn release in soils but not rocks and minerals.Moreover,LMWOLs are important for Mn dissolution,even under acidic pH conditions.展开更多
基金We acknowledge the financial support from State Key Laboratory of Pollution Control and Resource Reuse Foundation （No. PCRRF14017）, the National Natural Science Foundation of China （No. 21210004） and the China Postdoctoral Science Foundation （No. 2014M551455）. J. P. Y. appreciates the funding supported by the Commonwealth of Australia through the Automotive Australia 2020 Cooperative Research Centre （Auto CRC） and DP120101194. The authors would like to thank Dr. T. Silver for critical reading of this manuscript.
文摘The rational design and precise synthesis of multifunctional hybrid nanostructures with a tailored active core and a large, dendritic, modified mesoporous structured shell can promote catalysis, energy storage, and biological applications. Here, an oil-water biphase stratification coating strategy has been developed to prepare monodisperse magnetic dendritic mesoporous silica core-shell structured nano- spheres. These sophisticated Fe3O4@SiO2@dendritic-mSiO2 nanospheres feature large dendritic open pores （2.7 and 10.3 nm）. Significantly, the silica shells can be converted into dendritic mesoporous aluminosilicate frameworks with unchanged porosity, a Si/Al molar ratio of 14, and remarkably strong acidic sites, through a post-synthesis approach. In addition, the resultant magnetic dendritic mesoporous aluminosilicate nanospheres exhibit outstanding properties and promising application in phosphate removal from wastewater.
文摘The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses （x = 0 to 7 mol%） are investigated. Both Raman and IR spectra reveal that discrete phosphate species （[PO4]-3, [PO3O1/2]-2） with low polymerization degree can be formed in the silicate glass. These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network, resulting in an increase of the glass transi- tion temperature. According to the Judd-Ofelt intensity parameters （Ω2,Ω4, Ω6） of Er3＋, the asymmetry of local environment around Er3＋ becomes higher, and the bond covalency between Er3＋ and O2-decreases after P2O5 is introduced. In the emission spectra, photoluminescence intensity increases with increasing P2O5 concentration and the spectra are inhomogeneously broadened, revealing that the ligand electric field around Er3＋ is dramatically changed, and the glass matrix becomes disordered.
基金support through the research programs(Grant Nos.DQzX-KY-21-008,KYWX-21-023,and KYWX-21-022).
文摘Well-ordered aluminosilicates(MAs)were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale,and applied in an industrial fluid catalytic cracking unit for the first time.Compared with incumbent equilibrium catalyst,the surface area of trial equilibrium catalysts(30%inventory ratio)increased from 110 m^(2)g^(-1)to 120m^(2)g^(-1).Moreover,a significant increase of the mesoporous surfaceareaof trial equlibrium catalysts(30%inventoryrati)from 33 m g/to 40magi(22%increase).Furthermore,the equilibrium catalyst that contain 80%LPC-65 yields significantly lower heavy oil(0.23%)and higher total liquids(0.53%)compared with LDO-70.The industrial results demonstrated excellent hydrothermal stability and superior catalytic cracking properties,showing the promising futurein the industrial units.
基金supported by the National Natural Science Foundation of China(Nos.60937003 and 61111120100)
文摘The effects of bismuth doping content and temperature on the absorption property and near-infrared （NIR） luminescence of Bi-doped La2O3-Al2O3-SiO2 （LAS） glasses are presented. The emission intensity reaches the maximum when the Bi2O3 content in 3.0Bi-LAS is 1.83%. The emission spectra reach their peaks at 1 190 and 1 117 nm, with full-width at half-maximum （FWHM） values of 330 and 228 nm under 500 and 700-nm excitations, respectively. As the Bi203 content increases, the peak wavelengths and FWHMs of emission bands increase, but their lifetimes decrease. The lifetime of 2.0Bi-LAS is 460 μs at 9 K, and is almost temperature independent until 350 K. The NIR emission of Bi in the system has strong resistance to thermal quenching from 9 to 350 K.
文摘A unique templating approach for the synthesis of hexagonal mesoporous aluminosilicates via self assembly of pre formed aluminosilcate nanoclusters with the templating micella formed by cetyltrimethylammonium bromide (CTAB) is described. The obtained materials of MAS 5 are hydrothermally stable, which is shown by X ray diffraction (XRD) analysis. Furthermore, as characterized by NMR technique, MAS 5 has stable tetrahedral aluminum sites that is the major contributions to the acidity of aluminosilicate molecular sieve, and on non framework aluminium species in the samples was observed.
文摘In this study the characterization of an aluminosilicate synthesized from commercial Al2(SO4)3 and colloidal SiO2 is presented, as well as its capacity for the removal of copper from aqueous solution. Characterization of the synthesized material was performed using X-ray diffraction, BET nitrogen adsorption-desorption, mass titration and the Boehm method. In order to obtain stable agglomeration and enhance its surface area (165 - 243 m2/g) and solid adsorbing capabilities, the molar ratio SiO2:Al2O3 (1:3, 1:1 and 3:1) was studied, the solubility of the preparation material, synthesis-procedure time and solution pH function were also examined. The maximum capacity to remove copper ions from an aqueous solution by synthesized aluminosilicate was 16 mg/g at pH 4 and 25℃. The Langmuir model fitted better to the copper adsorption experimental data.
基金Supported by National Basic Research Program of China (Grant No. 2006CB202507)National High-tech R&D Program (Grant No. 2006AA02Z209)the National Natural Science Foundation of China (Grant No. 20806086)
文摘Mesoporous aluminosilicates (MAS) bearing microporous zeolite units and mesoporous structures were synthesized by the hydrothermal method. Adsorptive desulfurization ability of model oil and hy-drotreated diesel was studied. The effects of template concentration, crystalization time and calcination time were investigated. The desulfurization ability of adsorbents was improved by transitional metal ion-exchanging. The adsorptive desulfurization of diesel was carried out on a fixed-bed system. The results show that the adsorptive capacity is MAS>MCM-41>NaY. The improvement of desulfurization ability of MAS by Cu+ is more significant than that of Ag+.
文摘Low-cost adsorbents constituted by Fe-modified-aluminosilicates （laminar and zeolite type minerals） were developed and characterized to be used in the arsenic removal from groundwater. Iron activation was carried out ＂in situ＂ by the synthesis and deposition of mesoporous ferrihydrite. Natural iron-rich aluminosilicate was used as reference. All samples were characterized by X-ray diffraction, Raman spectroscopy, BET N2-adsorption, SEM-EDS microscopy and ICP chemical analysis. Experimental results of arsenic sorption showed that iron-poor raw materials were not active, unlike iron activated samples. The iron loading in all activated samples was below 5% （expressed as Fe203）, whereas the removal capacity of these samples reaches between 200-700 gg of As by g of adsorbent, after reusing between 17 cycles and 70 cycles up to adsorbent saturation. Differences can be associated to mineral structure and to the surface charge modification by iron deposition, affecting the attraction of the As-oxoanion. On the basis of low-cost raw materials, the easy chemical process for activation shows that these materials are potentially attractive for As（V） removal. Likewise, the activation of clay minerals, with natural high content of iron, seems to be a good strategy to enhance the arsenic adsorption ability and consequently the useful life of the adsorbent.
文摘Cementitious alkali activated aluminosilicates pastes were produced from recycled and locally obtainable materials in Iraq. The compositions were based on recycled bricks, water glass, commercial caustic soda flakes, and nano silica. The nano silica was prepared from the abundant local ＂Iraqi anber＂ rice husks and added to the prepared pastes in different weight percentages. Another set of pastes was prepared via adding 5w% of＂A1-Najaf＇ fly ash at the expense of the recycled bricks powders. The pastes were cured for 1-28 days under ambient conditions. The compressive strengths for the cured pastes were measured. In addition, the cured pastes were characterized via X-ray diffraction, FTIR, and optical microscopy. The addition of the nano silica and longer curing times improve the microstructure packing and thus increases the compressive strengths. The added fly ash impregnates the microstructure with extra gel phase and further improves the compressive strengths of the cured pastes.
基金the National Science Foundation Grants (NSF-1360760) to the Critical Zone Observatory Network National Office and NSF-1660923 to Dr.Louis A.Derry through a subaward to Dr.Justin B.Richardson。
文摘Manganese is ubiquitous in terrestrial environments and most studies have focused on dissolution of Mn oxides,but aluminosilicates also release Mn.Here,we evaluated oxic Mn dissolution from six rocks and minerals(amphibolite,anorthosite,kaolinite,kyanite,muscovite,orthoclase feldspar) and soils from four Critical Zone Observatories(CZOs) under four LMWOLs treatments(catechol,citric acid,oxalic acid,control).Overall rock and mineral Mn mass-normalized release was 1.4 ± 0.5 nM μM^(-1) 14 d^(-1) and dissolution rate was 2403 ± 935 nM m^(-2) d^(-1) x 10^(3).Overall CZO soil Mn release was 16.7±5.1 nM μM^(-1) 14 d^(-1) and dissolution rate was 7010 ± 2570 nM m^(-2) d^(-1) × 10^(3).Anorthosite and kyanite had the highest Mn dissolution rates but kaolinite and kyanite had the highest Mn mass-normalized release rates.We hypothesize the structural location of Mn,surface area,and potential inclusions of highly-weatherable-phases control Mn dissolution for rocks and minerals.CZO soils with the highest solid phase Mn had the highest Mn release and dissolution rates.Citric acid and catechol had higher Mn release and dissolution rates than the control while oxalic acid did not.For rocks and minerals,we found pH 4 had higher Mn release and dissolution rates than pH6,but not for control treatments without LMWOL.Our study highlights that the abundance of Mn drove Mn release in soils but not rocks and minerals.Moreover,LMWOLs are important for Mn dissolution,even under acidic pH conditions.
