Bismuth-promoted （1% and 3%） vanadyl pyrophosphate catalysts were prepared by refluxing Bi（NO3）4.5H2O and VOPO4.2H2O in isobutanol. The incorporation of Bi into the catalysts lattice increased the surface area and...Bismuth-promoted （1% and 3%） vanadyl pyrophosphate catalysts were prepared by refluxing Bi（NO3）4.5H2O and VOPO4.2H2O in isobutanol. The incorporation of Bi into the catalysts lattice increased the surface area and lowered the overall V oxidation state. Profiles of temperature programmed reduction （TPR） in H2 show a significant shift of the maxima of major reduction peaks to lower temperatures for the Bi-promoted catalysts. A new peak was also observed at the low temperature region for the catalyst with 3% of Bi dopant. The addition of Bi also increased the total amount of oxygen removed from the catalysts. The reduction pattern and reactivity information provide fundamental insight into the catalytic properties of the catalysts. Bi-promoted catalysts were found to be highly active （71% and 81% conversion for 1% and 3% Bi promoted catalysts, respectively, at 703 K）, as compared to the unpromoted material （47% conversion）. The higher activity of the Bi-promoted catalysts is due to that these catalysts possess highly active and labile lattice oxygen. The better catalytic performance can also be attributed to the larger surface area.展开更多
The present paper deals with the kinetics of polymerization of acrylonitrile (AN) initialed by the redox system of polypropylene-based vanadyi polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the tempe...The present paper deals with the kinetics of polymerization of acrylonitrile (AN) initialed by the redox system of polypropylene-based vanadyi polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the temperature range from 25 to 40℃. The polymerization rate was measured by varying the concentrations of monomer, vanadyl polyimidodiacetate, thiourea and sulfuric acid. The overall rate of polymerization was summarized asRp=2.2×10~5e^(-6.560/RT) [AN]^(1.0)[PV]^(0.50)[TU]^(1.5)[H_2SO_4]^(2.0)The molecular weight of polyacrylonitrile based on the experimental data was:(?)=k 1/T [pv]^(0.50)[TU]^(1.5)[H_2SO_4]^(2.0)These results indicated that the chain radicals are terminated by combination and/or disproportionation rather than chain transfer. The cooperation effect of carboxylic groups and the macromolecular field effect of polymer supporter are the characters of vanadyl polyimidodiacetate such as the case reported in early paper.展开更多
The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by ' cage ' vanadyl polycarboxylate (P=VO)-thiourea (TU) complex was investigated. The overall rate ofpolymerization isThe relationship...The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by ' cage ' vanadyl polycarboxylate (P=VO)-thiourea (TU) complex was investigated. The overall rate ofpolymerization isThe relationship between the induction period (τ) and the temperature of polymerization as well as the concentrations of reactants can be expressed as follows :The molecular weight of polyacrylonitrile increases with increasing monomer concentration and decreases with increasing temperature of polymerization and concentrations of vanadyl polycarboxylate and thioureaThe polymerization mechanism was proposed and discussed.展开更多
Dispersive liquid-liquid microextraction technique was introducd to remove the centrifuging step and conduct inclusion microextraction of charged porphyrins by nano-baskets. For nano-baskets of p-tert-calix[4]arene be...Dispersive liquid-liquid microextraction technique was introducd to remove the centrifuging step and conduct inclusion microextraction of charged porphyrins by nano-baskets. For nano-baskets of p-tert-calix[4]arene bearing di-[N-（X）sulfonyl carboxamide] and di-（1-propoxy） in ortho-cone conformation was synthesized and used. The related parameters including ligand concentration, the volume of water disperser, salt effect, and extraction time were optimized. The linear range, detection limit（S/N=3） and precision（RSD, n=6） were determined to be 0.2―50, 0.07 μg/L and 5.3%, respectively. The results reveal that the new approach is competitive analytical tool and an alternative of the traditional methods in the crude oil and related systems.展开更多
It remains an urgent task to develop alternative hole-transporting layer(HTL)materials beyond commonly used PEDOT:PSS to increase the shelf-life of organic solar cells(OSCs).Inorganic metal oxide type materials,such a...It remains an urgent task to develop alternative hole-transporting layer(HTL)materials beyond commonly used PEDOT:PSS to increase the shelf-life of organic solar cells(OSCs).Inorganic metal oxide type materials,such as NiO_(x),CoO_(x)and VO_(x),with suitable work functions have attracted numerous research attention recently.In this work,more abundant and easily accessible oxygenated salt,vanadyl sulfate(VOSO_(4))has been demonstrated to be excellent choice as HTL for OSCs.The VOSO_(4)-based HTL can be readily processed by spin-coating from the precursor solution with subsequent thermal annealing and UVO treatment.As a consequence,a high power conversion efficiency(PCE)of 18.72%can be achieved for PM8:L8-BO based OSCs with the VOSO_(4)-based HTL.High transmittance,smooth film surface,suitable energy level and high conductivity were revealed to contribute to the high OSC performance.More importantly,compared to device with PEDOT:PSS,VOSO_(4)-based OSCs exhibit improved stability when stored in the N_(2)filled glove box.After being stored for 600 h,VOSO_(4)-based device can retain 89%of its initial efficiency.Notably,VOSO_(4)can be used as general HTL in PM6:BTP-BO-4Cl and PM6:IT-4F based OSCs,yielding high PCEs of 17.87%and 13.85%,respectively.展开更多
The new vanadyl complex [VO（o-van）2（H2O）]（o-van=o-vanillin）was synthesized and characterized by IR,elemental analysis,and X-ray diffraction analysis.In the complex,the vanadium atom was coordinated to six oxygen...The new vanadyl complex [VO（o-van）2（H2O）]（o-van=o-vanillin）was synthesized and characterized by IR,elemental analysis,and X-ray diffraction analysis.In the complex,the vanadium atom was coordinated to six oxygen atoms and formed a distorted octahedral structure.The crystal belongs to monoclinic system with space group P21/n,a=0.9414（4）nm,b=1.6103（6） nm,c=1.1710（4）nm,β=111.493（6）°,V=1.6518（10）nm3,Z=4,DC=1.557 g·cm-3,F（000）=796,R1=0.0424,wR2=0.0842.展开更多
文摘Bismuth-promoted （1% and 3%） vanadyl pyrophosphate catalysts were prepared by refluxing Bi（NO3）4.5H2O and VOPO4.2H2O in isobutanol. The incorporation of Bi into the catalysts lattice increased the surface area and lowered the overall V oxidation state. Profiles of temperature programmed reduction （TPR） in H2 show a significant shift of the maxima of major reduction peaks to lower temperatures for the Bi-promoted catalysts. A new peak was also observed at the low temperature region for the catalyst with 3% of Bi dopant. The addition of Bi also increased the total amount of oxygen removed from the catalysts. The reduction pattern and reactivity information provide fundamental insight into the catalytic properties of the catalysts. Bi-promoted catalysts were found to be highly active （71% and 81% conversion for 1% and 3% Bi promoted catalysts, respectively, at 703 K）, as compared to the unpromoted material （47% conversion）. The higher activity of the Bi-promoted catalysts is due to that these catalysts possess highly active and labile lattice oxygen. The better catalytic performance can also be attributed to the larger surface area.
文摘The present paper deals with the kinetics of polymerization of acrylonitrile (AN) initialed by the redox system of polypropylene-based vanadyi polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the temperature range from 25 to 40℃. The polymerization rate was measured by varying the concentrations of monomer, vanadyl polyimidodiacetate, thiourea and sulfuric acid. The overall rate of polymerization was summarized asRp=2.2×10~5e^(-6.560/RT) [AN]^(1.0)[PV]^(0.50)[TU]^(1.5)[H_2SO_4]^(2.0)The molecular weight of polyacrylonitrile based on the experimental data was:(?)=k 1/T [pv]^(0.50)[TU]^(1.5)[H_2SO_4]^(2.0)These results indicated that the chain radicals are terminated by combination and/or disproportionation rather than chain transfer. The cooperation effect of carboxylic groups and the macromolecular field effect of polymer supporter are the characters of vanadyl polyimidodiacetate such as the case reported in early paper.
基金This project is supported by the National Natural Science Foundation of China.
文摘The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by ' cage ' vanadyl polycarboxylate (P=VO)-thiourea (TU) complex was investigated. The overall rate ofpolymerization isThe relationship between the induction period (τ) and the temperature of polymerization as well as the concentrations of reactants can be expressed as follows :The molecular weight of polyacrylonitrile increases with increasing monomer concentration and decreases with increasing temperature of polymerization and concentrations of vanadyl polycarboxylate and thioureaThe polymerization mechanism was proposed and discussed.
基金Supported by the Islamic Azad University(Shahreza Branch)the Iran Nanotechnology Initiative Council
文摘Dispersive liquid-liquid microextraction technique was introducd to remove the centrifuging step and conduct inclusion microextraction of charged porphyrins by nano-baskets. For nano-baskets of p-tert-calix[4]arene bearing di-[N-（X）sulfonyl carboxamide] and di-（1-propoxy） in ortho-cone conformation was synthesized and used. The related parameters including ligand concentration, the volume of water disperser, salt effect, and extraction time were optimized. The linear range, detection limit（S/N=3） and precision（RSD, n=6） were determined to be 0.2―50, 0.07 μg/L and 5.3%, respectively. The results reveal that the new approach is competitive analytical tool and an alternative of the traditional methods in the crude oil and related systems.
基金supported by NSFC(52163018,52073016,92163128)Jiangxi Provincial Department of Science and Technology(No.20212BCJ23035)+1 种基金Jiangxi Academy of Sciences(2023YJC1001,2023YSBG22025,2022YRCS002)the Hong Kong scholar program(XJ2022019)。
文摘It remains an urgent task to develop alternative hole-transporting layer(HTL)materials beyond commonly used PEDOT:PSS to increase the shelf-life of organic solar cells(OSCs).Inorganic metal oxide type materials,such as NiO_(x),CoO_(x)and VO_(x),with suitable work functions have attracted numerous research attention recently.In this work,more abundant and easily accessible oxygenated salt,vanadyl sulfate(VOSO_(4))has been demonstrated to be excellent choice as HTL for OSCs.The VOSO_(4)-based HTL can be readily processed by spin-coating from the precursor solution with subsequent thermal annealing and UVO treatment.As a consequence,a high power conversion efficiency(PCE)of 18.72%can be achieved for PM8:L8-BO based OSCs with the VOSO_(4)-based HTL.High transmittance,smooth film surface,suitable energy level and high conductivity were revealed to contribute to the high OSC performance.More importantly,compared to device with PEDOT:PSS,VOSO_(4)-based OSCs exhibit improved stability when stored in the N_(2)filled glove box.After being stored for 600 h,VOSO_(4)-based device can retain 89%of its initial efficiency.Notably,VOSO_(4)can be used as general HTL in PM6:BTP-BO-4Cl and PM6:IT-4F based OSCs,yielding high PCEs of 17.87%and 13.85%,respectively.
文摘The new vanadyl complex [VO（o-van）2（H2O）]（o-van=o-vanillin）was synthesized and characterized by IR,elemental analysis,and X-ray diffraction analysis.In the complex,the vanadium atom was coordinated to six oxygen atoms and formed a distorted octahedral structure.The crystal belongs to monoclinic system with space group P21/n,a=0.9414（4）nm,b=1.6103（6） nm,c=1.1710（4）nm,β=111.493（6）°,V=1.6518（10）nm3,Z=4,DC=1.557 g·cm-3,F（000）=796,R1=0.0424,wR2=0.0842.
