The three-dimensional(3D) Pd-based nanoflower structures,assembled from two-dimensional(2D)nanosheets,are characterized by their stable and ordered configurations.These structures have been extensively designed as ano...The three-dimensional(3D) Pd-based nanoflower structures,assembled from two-dimensional(2D)nanosheets,are characterized by their stable and ordered configurations.These structures have been extensively designed as anode materials for fuel cells.However,the exploration of trimetallic nanoflowers with porous architectures remains limited.In this study,we present a straightforward one-step solvothermal method for the synthesis of trimetallic Pd Cu Ni porous nanoflowers(PNFs).Leveraging several unique advantages,such as an open superstructure,high porosity,and enhanced electronic interactions among the trimetals,the resulting Pd Cu Ni PNFs demonstrate significantly improved electrochemical performance,with mass activities reaching 5.94 and 10.14 A/mg for the ethanol oxidation reaction(EOR)and the ethylene glycol oxidation reaction(EGOR),respectively.Furthermore,the Pd Cu Ni PNFs exhibit optimized d-band centers and the most negative onset oxidation potential,indicating enhanced antitoxicity and stability.This study not only provides a novel perspective on the synthesis of 3D porous nanomaterials but also highlights the potential application value of trimetallic nanoalloys in catalysis.展开更多
A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temp...A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temperature.Pt@ZIF-8 was highly porous and well crystallized.The Pt nanoparticles were well dispersed within the ZIF-8 support.In the hydrogenation of 1,4-butynediol,Pt@ZIF-8 exhibited high activity,excellent selectivity for 1,4-butenediol of greater than 94%,and reusability.The Pt@ZIF-8 catalyst did not require further additives.The favorable catalytic performance was attributed primarily to the modification of the ZIF-8 support by the platinum nanoparticles.展开更多
The research of superior water oxidation electrodes is essential for the green energy in the form of hydrogen by way of electrolytic water splitting, and still remains challenging. Based upon dealloying foam, Fe-Ni hy...The research of superior water oxidation electrodes is essential for the green energy in the form of hydrogen by way of electrolytic water splitting, and still remains challenging. Based upon dealloying foam, Fe-Ni hydroxide nanosheets network structure is designed on the surface of Fe-Ni alloy foam. The ratio of Ni/Fe elements was adjusted to realize the optimal catalytic activities for oxygen evolution reaction（OER） and hydrogen evolution reaction（HER）. The obtained electrode of Fe-Ni hydroxide nanosheets/Fe-Ni alloy foam-60% Fe（FN LDH/FNF-60, 60 is the percentage of Fe content） possess low overpotential of 261 mV to reach 10 mA/cm;, small Tafel slope（85.5 mV/dec）, and superior long-term stability（remaining 10 mA/cm;for over 14 h without attenuation） toward OER in 1.0 mol/L KOH.Moreover, an alkaline water electrolyzer is constructed with the FN LDH/FNF-60 as anode and Ni（OH）;/Fe-Ni alloy foam-25% Fe(Ni（OH）;/FNF-25) as cathode, which displays superior electrolytic performance（affording 10 mA/cm;at 1.62 V） and lasting durability.展开更多
Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate （Cu（NO3）2...Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate （Cu（NO3）2） in octadecylamine （ODA） solvent. As anode materials for lithium ion batteries, the Cu2O@Cu composites obviously possess high specific capacity, excellent cyclic stability and rate capability. The coulombic efficiency is about 84% in the 1 st cycle and increases significantly up to 97.8% during successive cycles at various current densities. Even under a high current density of 500 mA g^-l, the discharge capacity of Cu2O@Cu composites remains up to 200 mAh g^-1. The excellent electrochemical properties are ascribed to the synergistic effect between high electronic conductivity and volume-buffering capacity of metallic copper composited with Cu2O.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composi...Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composite materials were synthesized by one-step synthesis method. The chemical composition, morphology, structure, and thermal properties were investigated by XRD, EDS, SEM, and DSC. The results show that NaCl can be absorbed by Al2O3particle from 800 to 900 ℃ for Al2O3particle surface is rich active structure. The results also indicate that the leakage of NaCl when the phase change can be prevented by Al2O3particles and the enthalpy of phase change of NaCl-Al2O3material is 362 J/g. The composites have an excellent heat storage capacity. Therefore, this study contributes to one new thought and method to prepare high temperature heat storage material and this material can be applied in future thermal engineering.展开更多
CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of Ce...CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of CeO_2–CaO–Pd/HZSM-5 was investigated to ensure that the kinetics experimental results were not significantly influenced by induction period and catalytic deactivation. A large number of kinetic data points(40 sets) were obtained over a range of temperature(240–300 °C), pressure(3–4 MPa), gas hourly space velocity(GHSV)(2000–3000 L·kg^(-1)·h^(-1)) and H_2/CO mole ratio(2–3). Kinetic model for the methanol synthesis reaction and the dehydration of methanol were obtained separately according to reaction mechanism and Langmuir–Hinshelwood mechanism. Regression parameters were investigated by the method combining the simplex method and Runge–Kutta method. The model calculations were in appropriate accordance with the experimental data.展开更多
Herein we report a new general method for one-step synthesis of four kinds of fluoroiodane(Ⅲ)reagents by treating the corresponding aryl iodides with silver difluoride(AgF_(2)).This is the first method applicable for...Herein we report a new general method for one-step synthesis of four kinds of fluoroiodane(Ⅲ)reagents by treating the corresponding aryl iodides with silver difluoride(AgF_(2)).This is the first method applicable for the synthesis of all four fluoroiodane(Ⅲ)reagents including p-iodotoluene difluoride(1),fluoro-benziodoxole(2),fluoro-benziodoxolone(3),and fluoro-N-acetylbenziodazole(4).AgF_(2)was firstly employed in the direct oxidative fluorination of iodobenzene and thus has shown its outstanding oxidation and fluorine-transfer ability.The use of AgF_(2)has improved the synthesis of fluoroiodane(Ⅲ)reagents by shortening the reaction steps,avoiding the use of hazardous reagents,and simplifying the experimental operations.It was worth noting that we have developed the first one-step direct synthetic method for 3,while 3 can only be synthesized through Cl→F ligand exchange reaction previously.展开更多
MnO2 was doped into a conducting copolymer, poly（aniline-co-o-aminophenol） （PANOA）, via a one-step process during the chemical oxidative polymerization. The doping of MnO2 could enhance the electrochemical activit...MnO2 was doped into a conducting copolymer, poly（aniline-co-o-aminophenol） （PANOA）, via a one-step process during the chemical oxidative polymerization. The doping of MnO2 could enhance the electrochemical activity and reversibility of the copolymer. When used as the electrode materials of a supercapacitor, the capacitive behaviors of the as-prepared PANOA-MnO2 were superior to those of pure PANOA, especially at high potential scan rate and high charge-discharge current density. The MnO2 doped copolymer also had an excellent cyclic performance.展开更多
Perovskite LaMnO3 powders with an average crystallite size of 12.5 nm were rapidly synthesized via a microwave-induced autocombustion reaction using glycine as a fuel and nitrate as an oxidant. After self-propagating ...Perovskite LaMnO3 powders with an average crystallite size of 12.5 nm were rapidly synthesized via a microwave-induced autocombustion reaction using glycine as a fuel and nitrate as an oxidant. After self-propagating combustion, the desired nanocrystalline perovskite LaMnO3 was obtained and no further calcination was carried out. The possible processes of combustion reaction were discussed according to the principle of propellant chemistry. The autocombustion and thermal decomposition of the precursor were investigated using the TG-DTA and FT-IR techniques. The influences of glycine-nitrate molar ratio and heat-treatment temperature on the perovskite phase formation and crystallite size of as-burnt powder were studied by XRD. The morphology and size of the as-burnt powder before and after milling were characterized and compared by TEM.展开更多
ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production...ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production of caprolactam are based on either benzene or tolueneI21. Caprolactam is synthesized by the Beckmann rearrangement of cyclohexanone oxime with fuming sulfuric acid or sulfuric acid as the reaction medium, and cyclohexanone oxime is produced by the reaction between cyclohexanone and hydro- xylamine（only one exception is the Toray PNC process）.展开更多
Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant sol...Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.展开更多
A series of graphitic-C3N4/ZnS（g-C3N4/ZnS） supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The ...A series of graphitic-C3N4/ZnS（g-C3N4/ZnS） supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C3N4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, gC3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C3N4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C3N4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C3N4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.展开更多
Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent....Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent. The shapes of gold NPs were controllable by simply tuning S/Au ratio （S is from MSA molecule, and S/Au ratio is controlled by tuning the volume of added MSA solution）, and triangle, polygonal and spherical nanoparticles were obtained. This result suggested a new way to consider the effects of MSA on the growth of nanoparticles, which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension. And other important factors on nanoparticles growth including NaCl and temperature were discussed. Furthermore, a typical probe molecule, 4-aminothiophenol （4-ATP） was used to test the surface-enhanced Raman scattering （SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates. And the enhancement factor （EF） at 1078 cm^- 1 （a1） was estimated to be as large as 6.3 × 10^4 and 5.5 × 10^4 for triangular plates and truncated particles, respectively.展开更多
CoSn（OH）6 nanocubes were synthesized by a facile one-step co-precipitate method. Their supercapacitor performances were investigated via a traditional threeelectrode system and all solid-state flexible asymmetric su...CoSn（OH）6 nanocubes were synthesized by a facile one-step co-precipitate method. Their supercapacitor performances were investigated via a traditional threeelectrode system and all solid-state flexible asymmetric supercapacitor. The electrode shows a maximum specific capacitance up to 695 F·g^-1. The flexible all solid-state asymmetric supercapacitor was fabricated based on CoSn（OH）6 nanocubes and active carbon as positive and negative electrode. The assembled asymmetric supercapacitor exhibits a specific capacitance（97.3 mF·cm^-2）, good rate/mechanical stability and a long cycling stability（5000 cycles）, demonstrating great promise for applications in all solid-state flexible supercapacitors.展开更多
A thermodynamic model has been developed to determine the reaction conditions favoring low temperature direct synthesis of barium titanate (BaTiO3). The method utilizes standard-state thermodynamic data for solid and ...A thermodynamic model has been developed to determine the reaction conditions favoring low temperature direct synthesis of barium titanate (BaTiO3). The method utilizes standard-state thermodynamic data for solid and aqueous species and a 0ebye-Huckel coefficients model to represent solution nonideality. The method has been used to generate phase stability diagrams that indicate the ranges of pH and reagent concentrations, for which various species predominate in the system at a given temperature. Also, yield diagrams have been constructed that indicate the concentration, pH and temperature conditions for which different yields of crystalline BaTiO3 can be obtained. The stability and yield diagrams have been used to predict the optimum synthesis conditions (e.g., reagent concentrations, pH and temperature). Subsequently, these predictions have been experimentally verified. As a result, phase-pure perovskite BaTiO3 has been obtained at temperature ranging from 55 to 85℃ using BaCl2, TiCl4 as a source for Ba and Ti, and NaOH as a precipitator.展开更多
6-mercaptopurine(6-MP),a purine derivative(3,7-dihydropurine-6-thione),has been utilized as an effective immunosuppressive drug for clinically treating leukemia and other autoimmune diseases[1].6-MP and its correspond...6-mercaptopurine(6-MP),a purine derivative(3,7-dihydropurine-6-thione),has been utilized as an effective immunosuppressive drug for clinically treating leukemia and other autoimmune diseases[1].6-MP and its corresponding metabolites can suppress the function of RnaseH,and thus they are cytotoxic and threaten the human health[2].Therefore,the accurate quantification of 6-MP is crucial.To date,researchers continue to expend considerable effort in developing 6-MP detection methods.Fluorescence analysis eliminates disadvantages,such as toxic solvents,expensive equipment.展开更多
A one-step procedure is developed to synthesize inherently chiral p-tert-butylcalix[4]azacrown 1 through etherification between p-tert-butylcalix[4]arene and compound 3, which can be amplifed to efficiently prepare mo...A one-step procedure is developed to synthesize inherently chiral p-tert-butylcalix[4]azacrown 1 through etherification between p-tert-butylcalix[4]arene and compound 3, which can be amplifed to efficiently prepare more inherently cbiral calix[4]arenes in ABHH substitution pattern.展开更多
Creating adsorption sites by doping heteroatoms into the graphitic structures of carbon electrodes is an effective strategy for improving lithium storage in lithium-ion batteries.In this work,we prepared carbon nanotu...Creating adsorption sites by doping heteroatoms into the graphitic structures of carbon electrodes is an effective strategy for improving lithium storage in lithium-ion batteries.In this work,we prepared carbon nanotubes with controllable morphology and controllable nitrogen-doping level by a one-step pyrolysis method through adjusting the amount of urea used during synthesis.Under the synergistic effects of high temperature and Ni-catalyst migration,the carbon nanosheets generated by pyrolysis become coiled into tube-like structures.Characterization using Raman and x-ray photoelectron spectroscopy revealed that the B and N atoms were successfully co-doped into the resultant carbon nanotubes.When the obtained materials were used as lithium-ion battery anodes,reversible specific capacities of 337.11 and 187.62 mA h g^(−1) were achieved at current densities of 100 and 2000 mA g^(−1),respectively.Moreover,a capacity of 140.53 mA h g^(−1) was retained after 2000 cycles at a current density of 2000 mA g^(−1).The mechanism of lithium storage in these carbon materials was elucidated using cyclic voltammetry tests.Regarding other functional applications,the synthesized composite carbon nanotube material could also be used in other energy-storage battery systems,such as in the sulfur-carrying structures of lithium-sulfur batteries and in the three-dimensional porous structures of sodium batteries.展开更多
The first total synthesis of(-)-huperzine W(1)has been achieved.Key element of the synthesis is a highly convergent assemblage for the two rings system of target molecule utilizing an efficient Suzuki-Miyaura coupling...The first total synthesis of(-)-huperzine W(1)has been achieved.Key element of the synthesis is a highly convergent assemblage for the two rings system of target molecule utilizing an efficient Suzuki-Miyaura coupling reaction between chiral iodide 2 and 2-allylpyrrolidinone 4.Evaluation of the AchE inhibition of synthetic huperzine W was also carried out.展开更多
Titanium dioxide nanoparticles (TiO2) have been extensively investigated because of its high chemical sustainability, optic properties, and adaptation to the environment. These studies include applications in heteroge...Titanium dioxide nanoparticles (TiO2) have been extensively investigated because of its high chemical sustainability, optic properties, and adaptation to the environment. These studies include applications in heterogeneous catalysts, solar cells, coating technology, and electrical devices. TiO2 particles in the nanometer scale can remove limitations, such as the absorbance of organic materials, because of a high surface area to volume ratio. Titanium dioxide nanoparticles, were synthesized using a simple wet chemical method. Their physico-chemical properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The TEM results showed that the mean size of assynthesized TiO2 was 5 nm with high crystalline anatase phase. The SEM observations revealed that the size of nanoparticles increased with annealing temperature and the morphology of the particles changed to the spherical shape. The crystal structure of the nanoparticles before and after annealing was done by XRD analysis. The rutile phase was formed after heat treatment at 600oC for 3 hours.展开更多
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘The three-dimensional(3D) Pd-based nanoflower structures,assembled from two-dimensional(2D)nanosheets,are characterized by their stable and ordered configurations.These structures have been extensively designed as anode materials for fuel cells.However,the exploration of trimetallic nanoflowers with porous architectures remains limited.In this study,we present a straightforward one-step solvothermal method for the synthesis of trimetallic Pd Cu Ni porous nanoflowers(PNFs).Leveraging several unique advantages,such as an open superstructure,high porosity,and enhanced electronic interactions among the trimetals,the resulting Pd Cu Ni PNFs demonstrate significantly improved electrochemical performance,with mass activities reaching 5.94 and 10.14 A/mg for the ethanol oxidation reaction(EOR)and the ethylene glycol oxidation reaction(EGOR),respectively.Furthermore,the Pd Cu Ni PNFs exhibit optimized d-band centers and the most negative onset oxidation potential,indicating enhanced antitoxicity and stability.This study not only provides a novel perspective on the synthesis of 3D porous nanomaterials but also highlights the potential application value of trimetallic nanoalloys in catalysis.
基金supported by the National Natural Science Foundation of China(21573031 and 21428301)the Fundamental Research Funds for the Central Universities(DUT15ZD106 and DUT15RC(4)09)~~
文摘A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temperature.Pt@ZIF-8 was highly porous and well crystallized.The Pt nanoparticles were well dispersed within the ZIF-8 support.In the hydrogenation of 1,4-butynediol,Pt@ZIF-8 exhibited high activity,excellent selectivity for 1,4-butenediol of greater than 94%,and reusability.The Pt@ZIF-8 catalyst did not require further additives.The favorable catalytic performance was attributed primarily to the modification of the ZIF-8 support by the platinum nanoparticles.
基金supported by the Science and Technology Planning Project of Guangdong Province,China(No.2017B090916002)Tip-top Scientific and Technical Innovative Youth Talents of Guangdong Special Support Program(No.2016TQ03N541)+2 种基金Guangdong Natural Science Funds for Distinguished Young Scholar(No.2017B030306001)the National Natural Science Foundation of China(No.91745203)Guangdong Innovative and Entrepreneurial Research Team Program(No.2014ZT05N200)
文摘The research of superior water oxidation electrodes is essential for the green energy in the form of hydrogen by way of electrolytic water splitting, and still remains challenging. Based upon dealloying foam, Fe-Ni hydroxide nanosheets network structure is designed on the surface of Fe-Ni alloy foam. The ratio of Ni/Fe elements was adjusted to realize the optimal catalytic activities for oxygen evolution reaction（OER） and hydrogen evolution reaction（HER）. The obtained electrode of Fe-Ni hydroxide nanosheets/Fe-Ni alloy foam-60% Fe（FN LDH/FNF-60, 60 is the percentage of Fe content） possess low overpotential of 261 mV to reach 10 mA/cm;, small Tafel slope（85.5 mV/dec）, and superior long-term stability（remaining 10 mA/cm;for over 14 h without attenuation） toward OER in 1.0 mol/L KOH.Moreover, an alkaline water electrolyzer is constructed with the FN LDH/FNF-60 as anode and Ni（OH）;/Fe-Ni alloy foam-25% Fe(Ni（OH）;/FNF-25) as cathode, which displays superior electrolytic performance（affording 10 mA/cm;at 1.62 V） and lasting durability.
基金financially supported by the National Program on Key Basic Research Project (2014CB643403)National Key Research and Development Program of China (2017YFB0102900)the Shanghai Pujiang Program (17PJD016)
文摘Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate （Cu（NO3）2） in octadecylamine （ODA） solvent. As anode materials for lithium ion batteries, the Cu2O@Cu composites obviously possess high specific capacity, excellent cyclic stability and rate capability. The coulombic efficiency is about 84% in the 1 st cycle and increases significantly up to 97.8% during successive cycles at various current densities. Even under a high current density of 500 mA g^-l, the discharge capacity of Cu2O@Cu composites remains up to 200 mAh g^-1. The excellent electrochemical properties are ascribed to the synergistic effect between high electronic conductivity and volume-buffering capacity of metallic copper composited with Cu2O.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
基金Funded by the National Natural Science of China(No.2012BAA05B06)
文摘Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composite materials were synthesized by one-step synthesis method. The chemical composition, morphology, structure, and thermal properties were investigated by XRD, EDS, SEM, and DSC. The results show that NaCl can be absorbed by Al2O3particle from 800 to 900 ℃ for Al2O3particle surface is rich active structure. The results also indicate that the leakage of NaCl when the phase change can be prevented by Al2O3particles and the enthalpy of phase change of NaCl-Al2O3material is 362 J/g. The composites have an excellent heat storage capacity. Therefore, this study contributes to one new thought and method to prepare high temperature heat storage material and this material can be applied in future thermal engineering.
基金Supported by the National Natural Science Foundation of China(51204179,51204182,51674256)The Natural Science Foundation of Jiangsu Province,China(BK20141242)
文摘CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of CeO_2–CaO–Pd/HZSM-5 was investigated to ensure that the kinetics experimental results were not significantly influenced by induction period and catalytic deactivation. A large number of kinetic data points(40 sets) were obtained over a range of temperature(240–300 °C), pressure(3–4 MPa), gas hourly space velocity(GHSV)(2000–3000 L·kg^(-1)·h^(-1)) and H_2/CO mole ratio(2–3). Kinetic model for the methanol synthesis reaction and the dehydration of methanol were obtained separately according to reaction mechanism and Langmuir–Hinshelwood mechanism. Regression parameters were investigated by the method combining the simplex method and Runge–Kutta method. The model calculations were in appropriate accordance with the experimental data.
基金financially supported by the National Natural Science Foundation of China(Nos.21772096 and 22071116)the National Key Research and Development Program of China(No.2017YFD020030202)。
文摘Herein we report a new general method for one-step synthesis of four kinds of fluoroiodane(Ⅲ)reagents by treating the corresponding aryl iodides with silver difluoride(AgF_(2)).This is the first method applicable for the synthesis of all four fluoroiodane(Ⅲ)reagents including p-iodotoluene difluoride(1),fluoro-benziodoxole(2),fluoro-benziodoxolone(3),and fluoro-N-acetylbenziodazole(4).AgF_(2)was firstly employed in the direct oxidative fluorination of iodobenzene and thus has shown its outstanding oxidation and fluorine-transfer ability.The use of AgF_(2)has improved the synthesis of fluoroiodane(Ⅲ)reagents by shortening the reaction steps,avoiding the use of hazardous reagents,and simplifying the experimental operations.It was worth noting that we have developed the first one-step direct synthetic method for 3,while 3 can only be synthesized through Cl→F ligand exchange reaction previously.
基金the financial supports of National Natural Science Foundation of China(Nos.21275023,21173183)Natural Science Foundation of Jiangsu Province(No.BK2012593)+1 种基金Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology(No.BM2012110)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘MnO2 was doped into a conducting copolymer, poly（aniline-co-o-aminophenol） （PANOA）, via a one-step process during the chemical oxidative polymerization. The doping of MnO2 could enhance the electrochemical activity and reversibility of the copolymer. When used as the electrode materials of a supercapacitor, the capacitive behaviors of the as-prepared PANOA-MnO2 were superior to those of pure PANOA, especially at high potential scan rate and high charge-discharge current density. The MnO2 doped copolymer also had an excellent cyclic performance.
基金Project supported bythe National Natural Science Foundation of China (50306008) and the Fund fromthe Preli minary Research Project of General Equipment Ministry (41328030507)
文摘Perovskite LaMnO3 powders with an average crystallite size of 12.5 nm were rapidly synthesized via a microwave-induced autocombustion reaction using glycine as a fuel and nitrate as an oxidant. After self-propagating combustion, the desired nanocrystalline perovskite LaMnO3 was obtained and no further calcination was carried out. The possible processes of combustion reaction were discussed according to the principle of propellant chemistry. The autocombustion and thermal decomposition of the precursor were investigated using the TG-DTA and FT-IR techniques. The influences of glycine-nitrate molar ratio and heat-treatment temperature on the perovskite phase formation and crystallite size of as-burnt powder were studied by XRD. The morphology and size of the as-burnt powder before and after milling were characterized and compared by TEM.
基金Supported by the National Natural Science Foundation of China(Nos 20233040 and 20572021)
文摘ε-Caprolactam（CL or CPL） is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year^[1]. All current commercial processes for the production of caprolactam are based on either benzene or tolueneI21. Caprolactam is synthesized by the Beckmann rearrangement of cyclohexanone oxime with fuming sulfuric acid or sulfuric acid as the reaction medium, and cyclohexanone oxime is produced by the reaction between cyclohexanone and hydro- xylamine（only one exception is the Toray PNC process）.
基金Supported by the National Natural Science Foundation of China(21376229)the Science and Technology of Shanxi Province(2015031019-5)the Natural Science Foundation for Young Scientists of Shanxi Province(2015021033)
文摘Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.
基金supported by the National Nature Science Foundations of China (Grant no. 51372212)
文摘A series of graphitic-C3N4/ZnS（g-C3N4/ZnS） supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C3N4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, gC3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C3N4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C3N4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C3N4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.
基金supported by the National Natural Science Foundation of China under Grant No.21101146
文摘Gold nanoparticles （NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCl. 2-mercaptosuccinic acid （MSA） was used as both reducing agent and stabilizing agent. The shapes of gold NPs were controllable by simply tuning S/Au ratio （S is from MSA molecule, and S/Au ratio is controlled by tuning the volume of added MSA solution）, and triangle, polygonal and spherical nanoparticles were obtained. This result suggested a new way to consider the effects of MSA on the growth of nanoparticles, which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension. And other important factors on nanoparticles growth including NaCl and temperature were discussed. Furthermore, a typical probe molecule, 4-aminothiophenol （4-ATP） was used to test the surface-enhanced Raman scattering （SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates. And the enhancement factor （EF） at 1078 cm^- 1 （a1） was estimated to be as large as 6.3 × 10^4 and 5.5 × 10^4 for triangular plates and truncated particles, respectively.
基金financially supported by the Program for New Century Excellent Talents of the University in China (No. NCET-13-0645)the National Natural Science Foundation of China (Nos. 21201010, 21671170 and 21673203)+3 种基金the Innovation Scientists and Technicians Troop Construction Projects of Henan Province (No. 164200510018)the Program for Innovative Research Team (in Science and Technology) in University of Henan Province (No. 14IRTSTHN004)the Six Talent Plan (No. 2015-XCL-030)Qinglan Project
文摘CoSn（OH）6 nanocubes were synthesized by a facile one-step co-precipitate method. Their supercapacitor performances were investigated via a traditional threeelectrode system and all solid-state flexible asymmetric supercapacitor. The electrode shows a maximum specific capacitance up to 695 F·g^-1. The flexible all solid-state asymmetric supercapacitor was fabricated based on CoSn（OH）6 nanocubes and active carbon as positive and negative electrode. The assembled asymmetric supercapacitor exhibits a specific capacitance（97.3 mF·cm^-2）, good rate/mechanical stability and a long cycling stability（5000 cycles）, demonstrating great promise for applications in all solid-state flexible supercapacitors.
基金Supported by the National Natural Science Foundation of China (No. 20236020, No. 20325621)863 Hi-Technology Research and Development Program of China (No. 2001AA325014)the Talent Training Program of the Beijing City (No. 9558103500)the Fok Ying Tung Foundation (No. 81063).
文摘A thermodynamic model has been developed to determine the reaction conditions favoring low temperature direct synthesis of barium titanate (BaTiO3). The method utilizes standard-state thermodynamic data for solid and aqueous species and a 0ebye-Huckel coefficients model to represent solution nonideality. The method has been used to generate phase stability diagrams that indicate the ranges of pH and reagent concentrations, for which various species predominate in the system at a given temperature. Also, yield diagrams have been constructed that indicate the concentration, pH and temperature conditions for which different yields of crystalline BaTiO3 can be obtained. The stability and yield diagrams have been used to predict the optimum synthesis conditions (e.g., reagent concentrations, pH and temperature). Subsequently, these predictions have been experimentally verified. As a result, phase-pure perovskite BaTiO3 has been obtained at temperature ranging from 55 to 85℃ using BaCl2, TiCl4 as a source for Ba and Ti, and NaOH as a precipitator.
基金support of Taiyuan Institute of Technology Scientific Research Initial Funding,China(Grant No.:2022KJ058)the Basic Research Project of Shanxi Province,China(Project No.:202203021212331)+1 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi,China(Program Nos.:2022L529 and 2022L532)the Fund for Shanxi“1331”Project,China.
文摘6-mercaptopurine(6-MP),a purine derivative(3,7-dihydropurine-6-thione),has been utilized as an effective immunosuppressive drug for clinically treating leukemia and other autoimmune diseases[1].6-MP and its corresponding metabolites can suppress the function of RnaseH,and thus they are cytotoxic and threaten the human health[2].Therefore,the accurate quantification of 6-MP is crucial.To date,researchers continue to expend considerable effort in developing 6-MP detection methods.Fluorescence analysis eliminates disadvantages,such as toxic solvents,expensive equipment.
基金Foundation of Tianjin Medical University(No.2006x9d2)the National Natural ScienceFoundation of Chinathe Major State Basic Research Development Program of China(No.20502008) for financialsupport
文摘A one-step procedure is developed to synthesize inherently chiral p-tert-butylcalix[4]azacrown 1 through etherification between p-tert-butylcalix[4]arene and compound 3, which can be amplifed to efficiently prepare more inherently cbiral calix[4]arenes in ABHH substitution pattern.
文摘Creating adsorption sites by doping heteroatoms into the graphitic structures of carbon electrodes is an effective strategy for improving lithium storage in lithium-ion batteries.In this work,we prepared carbon nanotubes with controllable morphology and controllable nitrogen-doping level by a one-step pyrolysis method through adjusting the amount of urea used during synthesis.Under the synergistic effects of high temperature and Ni-catalyst migration,the carbon nanosheets generated by pyrolysis become coiled into tube-like structures.Characterization using Raman and x-ray photoelectron spectroscopy revealed that the B and N atoms were successfully co-doped into the resultant carbon nanotubes.When the obtained materials were used as lithium-ion battery anodes,reversible specific capacities of 337.11 and 187.62 mA h g^(−1) were achieved at current densities of 100 and 2000 mA g^(−1),respectively.Moreover,a capacity of 140.53 mA h g^(−1) was retained after 2000 cycles at a current density of 2000 mA g^(−1).The mechanism of lithium storage in these carbon materials was elucidated using cyclic voltammetry tests.Regarding other functional applications,the synthesized composite carbon nanotube material could also be used in other energy-storage battery systems,such as in the sulfur-carrying structures of lithium-sulfur batteries and in the three-dimensional porous structures of sodium batteries.
基金the National Natural Science of China(No.20802084,21072200)Programs of“One Hundred Talented People”and“Western Light”Joint Scholar of Chinese Academy of Sciences for financial support.
文摘The first total synthesis of(-)-huperzine W(1)has been achieved.Key element of the synthesis is a highly convergent assemblage for the two rings system of target molecule utilizing an efficient Suzuki-Miyaura coupling reaction between chiral iodide 2 and 2-allylpyrrolidinone 4.Evaluation of the AchE inhibition of synthetic huperzine W was also carried out.
文摘Titanium dioxide nanoparticles (TiO2) have been extensively investigated because of its high chemical sustainability, optic properties, and adaptation to the environment. These studies include applications in heterogeneous catalysts, solar cells, coating technology, and electrical devices. TiO2 particles in the nanometer scale can remove limitations, such as the absorbance of organic materials, because of a high surface area to volume ratio. Titanium dioxide nanoparticles, were synthesized using a simple wet chemical method. Their physico-chemical properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The TEM results showed that the mean size of assynthesized TiO2 was 5 nm with high crystalline anatase phase. The SEM observations revealed that the size of nanoparticles increased with annealing temperature and the morphology of the particles changed to the spherical shape. The crystal structure of the nanoparticles before and after annealing was done by XRD analysis. The rutile phase was formed after heat treatment at 600oC for 3 hours.
