Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source.Among several hydrogen production methods,it has become the most promising technology.However,there is no large-...Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source.Among several hydrogen production methods,it has become the most promising technology.However,there is no large-scale renewable hydrogen production system currently that can compete with conventional fossil fuel hydrogen production.Renewable energy electrocatalytic water splitting is an ideal production technology with environmental cleanliness protection and good hydrogen purity,which meet the requirements of future development.This review summarizes and introduces the current status of hydrogen production by water splitting from three aspects:electricity,catalyst and electrolyte.In particular,the present situation and the latest progress of the key sources of power,catalytic materials and electrolyzers for electrocatalytic water splitting are introduced.Finally,the problems of hydrogen generation from electrolytic water splitting and directions of next-generation green hydrogen in the future are discussed and outlooked.It is expected that this review will have an important impact on the field of hydrogen production from water.展开更多
Photochemical oxidation of thiophene in n-octane/water extraction system using O2 as oxidant was studied. The reaction mechanism ofthiophene oxidation was proposed. Results obtained here can be used as the reference f...Photochemical oxidation of thiophene in n-octane/water extraction system using O2 as oxidant was studied. The reaction mechanism ofthiophene oxidation was proposed. Results obtained here can be used as the reference for the oxidative desulfurization of gasoline because thiophene is one of the main components containing sulfur in fluid catalytic cracking gasoline. Thiophene dissolved in n-octane was photodecomposed and removed into the water phase at ambient temperature and atmospheric pressure. A 500 W high-pressure mercury lamp （main wave length 365 nm, 0.22 kW/m） was used as light source for irradiation, and air was introduced by a gas pump to supply O2. Thiophene can be photo-oxidized to sulfone, oxalic acid, SO4^2-, and CO2. The desulfurization yield of thiophene in n-octane is 58.9% under photo-irradiation for 5 h under the conditions of air flow at 150 mL/min and V（water）：V（n-octane）=1：1. It can be improved to 92.3% by adding 0.15 g zeoliteartificial into 100 mL reaction system, which is the adsorbent for O2 and thiophene. And under such conditions, the photo-oxidation kinetics of thiophene with O2/zeoliteartificial is first-order with an apparent rate constant of 0.5047 h^-1 and a half-time of 1.37 h. The sulfur content can be depressed from 800 μL/L to less than 62 μL/L.展开更多
Aqueous zinc-ion batteries(ZIBs)have got wide attention with the increasing demands for energy resource recently.It has a number of merits compared with lithium-ion batteries,such as enhanced safety,low cost and envir...Aqueous zinc-ion batteries(ZIBs)have got wide attention with the increasing demands for energy resource recently.It has a number of merits compared with lithium-ion batteries,such as enhanced safety,low cost and environmental friendliness.Vanadium-based materials have been developed to serve as the cathodes of ZIBs for many years.But there are also some challenges to construct high performance ZIBs in the future.Herein,we reviewed the research progress of vanadium-based cathodes and discussed the energy storage mechanisms in ZIBs.In addition,we summarized the major challenges faced by vanadium-based cathodes and the corresponding ways to improve electrochemical performance of ZIBs.Finally,some excellent vanadium-based cathodes are summarized to pave the way for future research in ZIBs.展开更多
The design, synthesis and biological evaluation of a novel series of arylpiperazine derivatives of diphenylsulfide with dual 5- HT1A/SSRI activities are reported. The target compounds exhibit low to moderate 5-HT tran...The design, synthesis and biological evaluation of a novel series of arylpiperazine derivatives of diphenylsulfide with dual 5- HT1A/SSRI activities are reported. The target compounds exhibit low to moderate 5-HT transporter affinity and moderate to high 5- HT1A affinity, Compound 13a shows moderate dual activities and is a promising lead compound for further structure-activity relationships studies.展开更多
The Qilian Block(QB)is a Precambrian micro-continent located in the northeastern Qinghai–Tibet Plateau.Prevalent Lower Paleozoic granitic magmatic rocks crop out in the QB.A new integrated study of zircon U-Pb ages a...The Qilian Block(QB)is a Precambrian micro-continent located in the northeastern Qinghai–Tibet Plateau.Prevalent Lower Paleozoic granitic magmatic rocks crop out in the QB.A new integrated study of zircon U-Pb ages and systematic whole-rock geochemical data for the Xindian,Dongjiazhuang and Xiaogaoling granites in the eastern segment of the QB constrains their emplacement ages,petrogenesis,and regional evolutionary history.U-Pb dating reveals that the Xindian granite was emplaced 454 Ma,and both the Dongjiazhuang and Xiaogaoling granites were emplaced ca.440 Ma.Geochemical study shows that all granites belong to the high-K calc-alkaline to shoshonitic series and are S-type granites formed by partial melting of continental crust,mainly metagraywacke.We infer that these ca.454–445 Ma granites formed in a syn-collisional setting during the continental collisional between the Qaidam and Qilian blocks.展开更多
Metal halide perovskite-based solar cells(PSCs) have rapidly-increased power conversion efficiency(PCE)exceeding 25% but poor stability especially under ultraviolet(UV) light. Meanwhile, non-radiative recombination ca...Metal halide perovskite-based solar cells(PSCs) have rapidly-increased power conversion efficiency(PCE)exceeding 25% but poor stability especially under ultraviolet(UV) light. Meanwhile, non-radiative recombination caused by diverse defects in perovskite absorbers and related interfaces is one of the major factors confining further development of PSCs. In this study, we systematically investigate the role of 2-(2-hydroxy-5-methylphenyl)benzotriazole(UVP) additive in perovskite layers. By adjusting the amount of doped UVP, the quality of perovskite absorbers is significantly improved with enlarged grains, longer lifetime and diffusion length of charge carriers. Furthermore, UVP not only reduces defects for less nonradiative recombination, but also matches energy level alignment for efficient interfacial charge extraction. X-ray photoelectron spectroscopy confirms that N-donor of UVP molecule coordinates with undercoordinated Pb^(2+) on the surface. Interestingly, UVP incorporated in PbI_(2) protects the perovskite by absorbing UV through the opening and closing of the chelating ring. Eventually, the UVP treated PSCs obtain a champion PCE of 22.46% with remarkably enhanced UV stability, retaining over 90% of initial PCE after 60 m W/cm^(2) strong UV irradiation for 9 h while the control maintaining only 74%. These results demonstrate a promising strategy fabricating passivated and UV-resistant perovskite materials simultaneously for efficient and stable perovskite photovoltaics.展开更多
Nano-F-/Ce3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Ce(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used to evaluate thei...Nano-F-/Ce3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Ce(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used to evaluate their photocatalytic activities. The powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersion X-ray spectrum (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis. The results showed that F- and Ce3+ were doped into TiO2. The appropriate content of fluorine and cerium were 2.0% and 1.0% (atom fraction) respectively. The codoped nano-F-/Ce3+/TiO2 particles had higher BET specific surface area, smaller crystallite size and higher photocatalytic activity than those of undoped TiO2 particles.展开更多
Blue luminescent compounds T1―T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1 H NMR,13 C NMR and high resolution mass spectrometry（HRMS）.Four co...Blue luminescent compounds T1―T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1 H NMR,13 C NMR and high resolution mass spectrometry（HRMS）.Four compounds T1―T4 exhibit excellent solubility in common solvents and good film forming properties.Quantum chemical calculations show that compounds T1―T4 have asymmetric linear structures and the proper highest occupied molecular orbital（HOMO） levels.The UV-Vis absorption and fluorescence emission spectra of the four compounds in dilute chloroform solutions and on the solid films were measured.It reveals that compounds T1―T4 exhibit similar spectral behavior,suggesting that these compounds can form amorphous state in solid films.The calculated absorption and emission spectra of compounds T1―T4 are in good agreement with experimentally determined ones.Compounds T1―T4 have absolute fluorescence quantum yield above 17% in dilute chloroform solutions.Four compounds possess high glass-transition temperature（T g） exceeding 97 ℃ and the maximum T g is 155.28 ℃ for compound T3.Cyclic voltammetry measurements show that these compounds have proper HOMO levels in a range of-5.01―-5.13 eV for hole injection.The properties of compounds T1―T4 indicate that these compounds are candidates for the application in organic light-emitting devices（OLEDs） as hole-transporting materials（HTMs）.展开更多
Five new cephalosporin compounds were designed and synthesized, and the antibacterial activities were evaluated by the standard serial 2-fold agar dilution method in vitro. The results showed that the activities of th...Five new cephalosporin compounds were designed and synthesized, and the antibacterial activities were evaluated by the standard serial 2-fold agar dilution method in vitro. The results showed that the activities of the compounds Ia and lb against ESBL E. coli and K. pneumoniae are comparable to those of Cefepime.展开更多
Nano-F-/Fe3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Fe(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used as a probe to ev...Nano-F-/Fe3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Fe(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used as a probe to evaluate their photocatalytic activities. The powders were characterized by X-ray diffraction(XRD),energy dispersion X-ray spectrum(EDS) and Brunauer-Emmett-Teller(BET) surface area analysis. The results show that F-and Fe 3+ are doped into TiO2. The F-and Fe3+ doping can help to enhance the nano-TiO2 photocatalytic activity greatly. The appropriate codoping conditions for F-Fe are n(F)/n(TiO2)=2%,n(Fe)/n(TiO2)=0.05%,and the degradation rate of methylene blue at 1 h is improved from 73.2% to 87.5%. The codoped nano-F-/Fe3+/TiO2 particles have higher BET specific surface area,smaller crystallite size and higher photocatalytic activity than those of undoped TiO2 particles.展开更多
A derivative of Brevianamide F,（3 S,8 a R）-3-（（1-allyl-1 H-3-indolyl）methyl）-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal stru...A derivative of Brevianamide F,（3 S,8 a R）-3-（（1-allyl-1 H-3-indolyl）methyl）-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal structure analysis. This compound crystallizes in orthorhombic system, space group P212121 with a = 9.59590（10）, b = 12.70430（10）, c = 14.5425（2） ?, V = 1772.86（3） ?3, Z = 4, μ（CuK α） = 0.712 mm-1, Dc = 1.279 g/cm3, 16019 reflections measured（9.24 o≤2θ≤147.28°）, 3524 unique（Rint = 0.0309, Rsigma = 0.0175） which were used in all calculations. The final R = 0.0567（I > 2σ（I）） and w R = 0.1411（all data）. The structure exhibits intermolecular hydrogen bonds typed O–H…O, leading to the formation of one-dimensional chains. The title compound was tested for inhibitory activity toward B-16, C6, RM-1 and BV-2 cancer cell lines.展开更多
Using a rigid azo ligand 4-[（8-hydroxy-5-quinolinyl）azo]-benzoic acid（H2 L）,a new supramolecular compound [Zn（L）（H2O）2]n（1） has been solvothermally synthesized and structurally characterized by X-ray single-...Using a rigid azo ligand 4-[（8-hydroxy-5-quinolinyl）azo]-benzoic acid（H2 L）,a new supramolecular compound [Zn（L）（H2O）2]n（1） has been solvothermally synthesized and structurally characterized by X-ray single-crystal diffraction,infrared spectrum,elemental analysis,power X-ray diffraction and thermal analysis.Compound 1 crystallizes in monoclinic,space group C2/c with a = 30.372（8）,b = 11.415（3）,c = 9.248（3） A,β = 106.94（3）o,V = 3067.20（15）A3,C（16）H（13）N3O5Zn,Mr = 392.66,Z = 8,Dc = 1.701 Mg/m^3; F（000） = 1600,μ = 1.636 mm^-1,reflections collected：7290,reflections unique：2735,R（int）= 0.0282,R = 0.0351,wR（all data） = 0.0919,GOOF on F^2 = 1.036.Compound 1 exhibits a one-dimensional（1 D） zig-zag chain structure connected into a three-dimensional（3D） supramolecular network through hydrogen bonding interactions.Fluorescent property and electrochemical property were detected on compound 1.展开更多
An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 （TS-1） in ambient-temper...An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 （TS-1） in ambient-temperature ionic liquid [emim]BF4. Good yield and higher selectivity of products were found in the ionic liquid compared with in molecular solvent. The research results showed 13.2% conversion of cyclohexane, 97.6% cyclohexanol and cyclohexanone selectivity were obtained in ionic liquid under mild conditions of 90℃.展开更多
The demand for efficient and environmentally-benign electrocatalysts that help availably harness the renewable energy resources is growing rapidly. In recent years, increasing insights into the design of water electro...The demand for efficient and environmentally-benign electrocatalysts that help availably harness the renewable energy resources is growing rapidly. In recent years, increasing insights into the design of water electrolysers, fuel cells, and metal–air batteries emerge in response to the need for developing sustainable energy carriers, in which the oxygen evolution reaction and the oxygen reduction reaction play key roles. However, both reactions suffer from sluggish kinetics that restricts the reactivity. Therefore, it is vital to probe into the structure of the catalysts to exploit high-performance bifunctional oxygen electrocatalysts. Spinel-type catalysts are a class of materials with advantages of versatility, low toxicity, low expense, high abundance, flexible ion arrangement, and multivalence structure. In this review, we afford a basic overview of spinel-type materials and then introduce the relevant theoretical principles for electrocatalytic activity, following that we shed light on the structure–property relationship strategies for spinel-type catalysts including electronic structure, microstructure, phase and composition regulation,and coupling with electrically conductive supports. We elaborate the relationship between structure and property, in order to provide some insights into the design of spinel-type bifunctional oxygen electrocatalysts.展开更多
The kinetics of esterification of 2-keto-L-gulonic acid with methanol in the liquid phase catalyzed by cation exchange resin, D001, was studied. The experiments were carried out in a stirred batch reactor at 318, 323,...The kinetics of esterification of 2-keto-L-gulonic acid with methanol in the liquid phase catalyzed by cation exchange resin, D001, was studied. The experiments were carried out in a stirred batch reactor at 318, 323, 328, 333, 338, 341 K under atmospheric pressure. It is found that the speed of rotating rate has no effect on the esterification rate in the range of 300-500 r/min and the effect of internal mass transfer resistance is not obvious. The effects of temperature and catalyst loading on the reaction rate were researched under the condition of eliminating the effect of diffusion. The rate was found to increase with the increase of the temperature and catalyst loading. The experimental data were correlated with a kinetic model based on the pseudo-homogeneous catalysis. The kinetic equation for describing the reaction catalyzed by cation exchange resin was developed. The experimental data are in good agreement with the model.展开更多
Phosphorus in energy storage has received widespread attention in recent years. Both the high specific capacity and ion mobility of phosphorus may lead to a breakthrough in energy storage materials. Black phosphorus, ...Phosphorus in energy storage has received widespread attention in recent years. Both the high specific capacity and ion mobility of phosphorus may lead to a breakthrough in energy storage materials. Black phosphorus, an allotrope of phosphorus, has a sheet-like structure similar to graphite. In this review, we describe the structure and properties of black phosphorus and characteristics of the conductive electrode material, including theoretical calculation and analysis. The research progress in various ion batteries, including lithium-sulfur batteries, lithium–air batteries, and supercapacitors, is summarized according to the introduction of black phosphorus materials in different electrochemical applications. Among them, with the introduction of black phosphorus in lithium-ion batteries and sodium-ion batteries, the research on the properties of black phosphorus and carbon composite is introduced. Based on the summary, the future development trend and potential of black phosphorus materials in the field of electrochemistry are analyzed.展开更多
In the light of wireless and non-fossil society based on portable electronics, electric vehicles, and smart grids, secondary batteries with higher energy density, faster charge, and safer operation are pursued persist...In the light of wireless and non-fossil society based on portable electronics, electric vehicles, and smart grids, secondary batteries with higher energy density, faster charge, and safer operation are pursued persistently [1]. Nowadays, commercial lithium(Li)-ion batteries have been practically applied in our daily life. However,the energy density of Li-ion batteries based on intercalation chemistry is approaching to the theoretical value due to the limited specific capacity of graphite anode(372 mA h g-1) [2].展开更多
The design of novel catalysts for efficient electroreduction of CO_(2) into valueadded chemicals is a promising approach to alleviate the energy crisis.Herein,we successfully modify the carbon nanotube by a layer of m...The design of novel catalysts for efficient electroreduction of CO_(2) into valueadded chemicals is a promising approach to alleviate the energy crisis.Herein,we successfully modify the carbon nanotube by a layer of mesoporous carbon shell anchored by nickel(Ni)nanoparticles.Ni species effectively enable carbon deposition derived from pyrolysis of surfactant 1-hexadecyl trimethyl ammonium bromide to form a mesoporous carbon shell.At the same time,Ni nanoparticles can be embedded in the mesoporous carbon shell due to the confinement effect.Owing to the dispersive Ni nanoparticles and N-doping active sites of mesoporous carbon,the as-prepared electrocatalyst exhibits exciting catalytic performance for the selective reduction of CO_(2) to carbon monoxide(CO)with a maximum Faradaic efficiency of 98%at a moderate overpotential of−0.81 V(vs.reversible hydrogen electrode)and a high partial current density of 60 mA cm^(−2) in H-cell with an aqueous electrolyte.展开更多
Electrochemical reduction of CO_(2)(CO_(2)ER) to formate has been a promising route to produce value-added chemicals.Developing low-cost and efficient electrocatalysts with high product selectivity is still a grand ch...Electrochemical reduction of CO_(2)(CO_(2)ER) to formate has been a promising route to produce value-added chemicals.Developing low-cost and efficient electrocatalysts with high product selectivity is still a grand challenge.Herein,a novel Ni nanoparticles-anchored CNT coated by mesoporous carbon with yolk-shell structure (CNT/Ni@mC) catalysis was designed for CO_(2)ER.Ni nanoparticles were confined in the cavity between CNT and mesoporous carbon shell and the confined space can be controlled by tuning the amount of silica precursor.The mesoporous carbon shell and confined space are beneficial to charge transmission during CO_(2)ER.In contrast to previous studies,the CNT/Ni@mC catalyst presents selectivity toward formate rather than CO.Electrochemical in situ attenuated total reflection Fourier transform infrared spectroscopy measurements indicate the presence of a COO* intermediate that converts to formate under CO_(2)ER conditions.The well-defined structural feature of the confined space of the Ni-based catalyst for selective CO_(2)ER to formate may facilitate in-depth mechanistic understandings on structural factors that affect CO_(2)ER performance.展开更多
基金supported by the National Natural Science Foundation of China(U23A20573,U23A20140,22109038)the Starting Research Funds of Hebei University of Science and Technology,Hebei Natural Science Foundation(D2022208001)+1 种基金the S&T Program of Hebei(23314401D)Hebei Pharmaceutical and Chemical Technology Innovation Center(225676121H).
文摘Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source.Among several hydrogen production methods,it has become the most promising technology.However,there is no large-scale renewable hydrogen production system currently that can compete with conventional fossil fuel hydrogen production.Renewable energy electrocatalytic water splitting is an ideal production technology with environmental cleanliness protection and good hydrogen purity,which meet the requirements of future development.This review summarizes and introduces the current status of hydrogen production by water splitting from three aspects:electricity,catalyst and electrolyte.In particular,the present situation and the latest progress of the key sources of power,catalytic materials and electrolyzers for electrocatalytic water splitting are introduced.Finally,the problems of hydrogen generation from electrolytic water splitting and directions of next-generation green hydrogen in the future are discussed and outlooked.It is expected that this review will have an important impact on the field of hydrogen production from water.
基金Science and Technology Development Planning Foundation of Jilin Province, China(No.20030405)
文摘Photochemical oxidation of thiophene in n-octane/water extraction system using O2 as oxidant was studied. The reaction mechanism ofthiophene oxidation was proposed. Results obtained here can be used as the reference for the oxidative desulfurization of gasoline because thiophene is one of the main components containing sulfur in fluid catalytic cracking gasoline. Thiophene dissolved in n-octane was photodecomposed and removed into the water phase at ambient temperature and atmospheric pressure. A 500 W high-pressure mercury lamp （main wave length 365 nm, 0.22 kW/m） was used as light source for irradiation, and air was introduced by a gas pump to supply O2. Thiophene can be photo-oxidized to sulfone, oxalic acid, SO4^2-, and CO2. The desulfurization yield of thiophene in n-octane is 58.9% under photo-irradiation for 5 h under the conditions of air flow at 150 mL/min and V（water）：V（n-octane）=1：1. It can be improved to 92.3% by adding 0.15 g zeoliteartificial into 100 mL reaction system, which is the adsorbent for O2 and thiophene. And under such conditions, the photo-oxidation kinetics of thiophene with O2/zeoliteartificial is first-order with an apparent rate constant of 0.5047 h^-1 and a half-time of 1.37 h. The sulfur content can be depressed from 800 μL/L to less than 62 μL/L.
基金supported by the Natural Science Foundation of Tianjin-Science and the Technology Correspondent Project(19YFSLQY00070)the State Key Laboratory of Organic-Inorganic Composites(oic-201901004)+1 种基金the National Natural Science Foundation of China(21676070)Hebei University of Science and Technology(20544401D,20314401D)。
文摘Aqueous zinc-ion batteries(ZIBs)have got wide attention with the increasing demands for energy resource recently.It has a number of merits compared with lithium-ion batteries,such as enhanced safety,low cost and environmental friendliness.Vanadium-based materials have been developed to serve as the cathodes of ZIBs for many years.But there are also some challenges to construct high performance ZIBs in the future.Herein,we reviewed the research progress of vanadium-based cathodes and discussed the energy storage mechanisms in ZIBs.In addition,we summarized the major challenges faced by vanadium-based cathodes and the corresponding ways to improve electrochemical performance of ZIBs.Finally,some excellent vanadium-based cathodes are summarized to pave the way for future research in ZIBs.
文摘The design, synthesis and biological evaluation of a novel series of arylpiperazine derivatives of diphenylsulfide with dual 5- HT1A/SSRI activities are reported. The target compounds exhibit low to moderate 5-HT transporter affinity and moderate to high 5- HT1A affinity, Compound 13a shows moderate dual activities and is a promising lead compound for further structure-activity relationships studies.
基金financially supported by the Qinghai Science and Technology Department(Grant No.2016-ZJ752)Qinghai Salt Lake Industry(Grant No.E050DZ0801)。
文摘The Qilian Block(QB)is a Precambrian micro-continent located in the northeastern Qinghai–Tibet Plateau.Prevalent Lower Paleozoic granitic magmatic rocks crop out in the QB.A new integrated study of zircon U-Pb ages and systematic whole-rock geochemical data for the Xindian,Dongjiazhuang and Xiaogaoling granites in the eastern segment of the QB constrains their emplacement ages,petrogenesis,and regional evolutionary history.U-Pb dating reveals that the Xindian granite was emplaced 454 Ma,and both the Dongjiazhuang and Xiaogaoling granites were emplaced ca.440 Ma.Geochemical study shows that all granites belong to the high-K calc-alkaline to shoshonitic series and are S-type granites formed by partial melting of continental crust,mainly metagraywacke.We infer that these ca.454–445 Ma granites formed in a syn-collisional setting during the continental collisional between the Qaidam and Qilian blocks.
基金financially supported by the National Key R&D Program of China(2018YFB1500105)the Natural Science Foundation of China(61874167)+3 种基金the Fundamental Research Funds for Central Universitiesthe 111 Project(B16027)the International Cooperation Base(2016D01025)the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720)for financial support。
文摘Metal halide perovskite-based solar cells(PSCs) have rapidly-increased power conversion efficiency(PCE)exceeding 25% but poor stability especially under ultraviolet(UV) light. Meanwhile, non-radiative recombination caused by diverse defects in perovskite absorbers and related interfaces is one of the major factors confining further development of PSCs. In this study, we systematically investigate the role of 2-(2-hydroxy-5-methylphenyl)benzotriazole(UVP) additive in perovskite layers. By adjusting the amount of doped UVP, the quality of perovskite absorbers is significantly improved with enlarged grains, longer lifetime and diffusion length of charge carriers. Furthermore, UVP not only reduces defects for less nonradiative recombination, but also matches energy level alignment for efficient interfacial charge extraction. X-ray photoelectron spectroscopy confirms that N-donor of UVP molecule coordinates with undercoordinated Pb^(2+) on the surface. Interestingly, UVP incorporated in PbI_(2) protects the perovskite by absorbing UV through the opening and closing of the chelating ring. Eventually, the UVP treated PSCs obtain a champion PCE of 22.46% with remarkably enhanced UV stability, retaining over 90% of initial PCE after 60 m W/cm^(2) strong UV irradiation for 9 h while the control maintaining only 74%. These results demonstrate a promising strategy fabricating passivated and UV-resistant perovskite materials simultaneously for efficient and stable perovskite photovoltaics.
基金the Natural Science Foundation of Hebei Province (203364)the Natural Science Foundation of Hebei University of Science and Technology (XL2006038)
文摘Nano-F-/Ce3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Ce(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used to evaluate their photocatalytic activities. The powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersion X-ray spectrum (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis. The results showed that F- and Ce3+ were doped into TiO2. The appropriate content of fluorine and cerium were 2.0% and 1.0% (atom fraction) respectively. The codoped nano-F-/Ce3+/TiO2 particles had higher BET specific surface area, smaller crystallite size and higher photocatalytic activity than those of undoped TiO2 particles.
基金Supported by the National High-Tech Research and Development Program of China(No.2008AA03A315)the Natural Science Foundation of Tianjin City,China(No.08JCZDJC16900)
文摘Blue luminescent compounds T1―T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1 H NMR,13 C NMR and high resolution mass spectrometry（HRMS）.Four compounds T1―T4 exhibit excellent solubility in common solvents and good film forming properties.Quantum chemical calculations show that compounds T1―T4 have asymmetric linear structures and the proper highest occupied molecular orbital（HOMO） levels.The UV-Vis absorption and fluorescence emission spectra of the four compounds in dilute chloroform solutions and on the solid films were measured.It reveals that compounds T1―T4 exhibit similar spectral behavior,suggesting that these compounds can form amorphous state in solid films.The calculated absorption and emission spectra of compounds T1―T4 are in good agreement with experimentally determined ones.Compounds T1―T4 have absolute fluorescence quantum yield above 17% in dilute chloroform solutions.Four compounds possess high glass-transition temperature（T g） exceeding 97 ℃ and the maximum T g is 155.28 ℃ for compound T3.Cyclic voltammetry measurements show that these compounds have proper HOMO levels in a range of-5.01―-5.13 eV for hole injection.The properties of compounds T1―T4 indicate that these compounds are candidates for the application in organic light-emitting devices（OLEDs） as hole-transporting materials（HTMs）.
文摘Five new cephalosporin compounds were designed and synthesized, and the antibacterial activities were evaluated by the standard serial 2-fold agar dilution method in vitro. The results showed that the activities of the compounds Ia and lb against ESBL E. coli and K. pneumoniae are comparable to those of Cefepime.
基金Project(203364) supported by the Natural Science Foundation of Hebei Province, Chinaproject(XL2006038) supported by the Natural Science Foundation of Hebei University of Science and Technology, China
文摘Nano-F-/Fe3+/TiO2 particles were prepared by hydrolysis of tetrabutyl titanate in a mixed CF3COOH-Fe(NO3)3-H2O solution. The photocatalytic decomposition of methylene blue in aqueous solution was used as a probe to evaluate their photocatalytic activities. The powders were characterized by X-ray diffraction(XRD),energy dispersion X-ray spectrum(EDS) and Brunauer-Emmett-Teller(BET) surface area analysis. The results show that F-and Fe 3+ are doped into TiO2. The F-and Fe3+ doping can help to enhance the nano-TiO2 photocatalytic activity greatly. The appropriate codoping conditions for F-Fe are n(F)/n(TiO2)=2%,n(Fe)/n(TiO2)=0.05%,and the degradation rate of methylene blue at 1 h is improved from 73.2% to 87.5%. The codoped nano-F-/Fe3+/TiO2 particles have higher BET specific surface area,smaller crystallite size and higher photocatalytic activity than those of undoped TiO2 particles.
基金financially sponsored by the Natural Science Foundation of Hebei Province(No.B2015208134)
文摘A derivative of Brevianamide F,（3 S,8 a R）-3-（（1-allyl-1 H-3-indolyl）methyl）-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal structure analysis. This compound crystallizes in orthorhombic system, space group P212121 with a = 9.59590（10）, b = 12.70430（10）, c = 14.5425（2） ?, V = 1772.86（3） ?3, Z = 4, μ（CuK α） = 0.712 mm-1, Dc = 1.279 g/cm3, 16019 reflections measured（9.24 o≤2θ≤147.28°）, 3524 unique（Rint = 0.0309, Rsigma = 0.0175） which were used in all calculations. The final R = 0.0567（I > 2σ（I）） and w R = 0.1411（all data）. The structure exhibits intermolecular hydrogen bonds typed O–H…O, leading to the formation of one-dimensional chains. The title compound was tested for inhibitory activity toward B-16, C6, RM-1 and BV-2 cancer cell lines.
基金Supported by the National Science Foundation of China(No.20831002 and 21531003)Project of Science and Technology Development of Jilin City(No.20166024)
文摘Using a rigid azo ligand 4-[（8-hydroxy-5-quinolinyl）azo]-benzoic acid（H2 L）,a new supramolecular compound [Zn（L）（H2O）2]n（1） has been solvothermally synthesized and structurally characterized by X-ray single-crystal diffraction,infrared spectrum,elemental analysis,power X-ray diffraction and thermal analysis.Compound 1 crystallizes in monoclinic,space group C2/c with a = 30.372（8）,b = 11.415（3）,c = 9.248（3） A,β = 106.94（3）o,V = 3067.20（15）A3,C（16）H（13）N3O5Zn,Mr = 392.66,Z = 8,Dc = 1.701 Mg/m^3; F（000） = 1600,μ = 1.636 mm^-1,reflections collected：7290,reflections unique：2735,R（int）= 0.0282,R = 0.0351,wR（all data） = 0.0919,GOOF on F^2 = 1.036.Compound 1 exhibits a one-dimensional（1 D） zig-zag chain structure connected into a three-dimensional（3D） supramolecular network through hydrogen bonding interactions.Fluorescent property and electrochemical property were detected on compound 1.
基金Supported by the National Natural Science Foundation of China （20776037）.
文摘An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 （TS-1） in ambient-temperature ionic liquid [emim]BF4. Good yield and higher selectivity of products were found in the ionic liquid compared with in molecular solvent. The research results showed 13.2% conversion of cyclohexane, 97.6% cyclohexanol and cyclohexanone selectivity were obtained in ionic liquid under mild conditions of 90℃.
基金supported by the Natural Scientific Foundation of China (21825501)National Key Research and Development Program (2016YFA0202500 and 2016YFA0200102)+1 种基金Australian Research Council (DP160103107, FT170100224)Tsinghua University Initiative Scientific Research Program。
文摘The demand for efficient and environmentally-benign electrocatalysts that help availably harness the renewable energy resources is growing rapidly. In recent years, increasing insights into the design of water electrolysers, fuel cells, and metal–air batteries emerge in response to the need for developing sustainable energy carriers, in which the oxygen evolution reaction and the oxygen reduction reaction play key roles. However, both reactions suffer from sluggish kinetics that restricts the reactivity. Therefore, it is vital to probe into the structure of the catalysts to exploit high-performance bifunctional oxygen electrocatalysts. Spinel-type catalysts are a class of materials with advantages of versatility, low toxicity, low expense, high abundance, flexible ion arrangement, and multivalence structure. In this review, we afford a basic overview of spinel-type materials and then introduce the relevant theoretical principles for electrocatalytic activity, following that we shed light on the structure–property relationship strategies for spinel-type catalysts including electronic structure, microstructure, phase and composition regulation,and coupling with electrically conductive supports. We elaborate the relationship between structure and property, in order to provide some insights into the design of spinel-type bifunctional oxygen electrocatalysts.
文摘The kinetics of esterification of 2-keto-L-gulonic acid with methanol in the liquid phase catalyzed by cation exchange resin, D001, was studied. The experiments were carried out in a stirred batch reactor at 318, 323, 328, 333, 338, 341 K under atmospheric pressure. It is found that the speed of rotating rate has no effect on the esterification rate in the range of 300-500 r/min and the effect of internal mass transfer resistance is not obvious. The effects of temperature and catalyst loading on the reaction rate were researched under the condition of eliminating the effect of diffusion. The rate was found to increase with the increase of the temperature and catalyst loading. The experimental data were correlated with a kinetic model based on the pseudo-homogeneous catalysis. The kinetic equation for describing the reaction catalyzed by cation exchange resin was developed. The experimental data are in good agreement with the model.
基金supported by Tianjin Science and Technology Project (No. 19YFSLQY00070)the Opening Foundation of State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology (No. oic-201901004).
文摘Phosphorus in energy storage has received widespread attention in recent years. Both the high specific capacity and ion mobility of phosphorus may lead to a breakthrough in energy storage materials. Black phosphorus, an allotrope of phosphorus, has a sheet-like structure similar to graphite. In this review, we describe the structure and properties of black phosphorus and characteristics of the conductive electrode material, including theoretical calculation and analysis. The research progress in various ion batteries, including lithium-sulfur batteries, lithium–air batteries, and supercapacitors, is summarized according to the introduction of black phosphorus materials in different electrochemical applications. Among them, with the introduction of black phosphorus in lithium-ion batteries and sodium-ion batteries, the research on the properties of black phosphorus and carbon composite is introduced. Based on the summary, the future development trend and potential of black phosphorus materials in the field of electrochemistry are analyzed.
基金supported by the National Key Research and Development Program (2016YFA0202500 and 2016YFA0200102)the National Natural Science Foundation of China (21676160, 21825501, and U1801257)Tsinghua University Initiative Scientific Research Program。
文摘In the light of wireless and non-fossil society based on portable electronics, electric vehicles, and smart grids, secondary batteries with higher energy density, faster charge, and safer operation are pursued persistently [1]. Nowadays, commercial lithium(Li)-ion batteries have been practically applied in our daily life. However,the energy density of Li-ion batteries based on intercalation chemistry is approaching to the theoretical value due to the limited specific capacity of graphite anode(372 mA h g-1) [2].
基金the Natural Science Foundation of Hebei(B02020208088,H2020206514)S&T Program of Hebei(20544401D,20314401D,206Z4406G,21314402D,B2021208074)+1 种基金Tianjin Science and Technology Project(19YFSLQY00070)Natural Science Foundation of Shandong Province(ZR2021MB104).
文摘The design of novel catalysts for efficient electroreduction of CO_(2) into valueadded chemicals is a promising approach to alleviate the energy crisis.Herein,we successfully modify the carbon nanotube by a layer of mesoporous carbon shell anchored by nickel(Ni)nanoparticles.Ni species effectively enable carbon deposition derived from pyrolysis of surfactant 1-hexadecyl trimethyl ammonium bromide to form a mesoporous carbon shell.At the same time,Ni nanoparticles can be embedded in the mesoporous carbon shell due to the confinement effect.Owing to the dispersive Ni nanoparticles and N-doping active sites of mesoporous carbon,the as-prepared electrocatalyst exhibits exciting catalytic performance for the selective reduction of CO_(2) to carbon monoxide(CO)with a maximum Faradaic efficiency of 98%at a moderate overpotential of−0.81 V(vs.reversible hydrogen electrode)and a high partial current density of 60 mA cm^(−2) in H-cell with an aqueous electrolyte.
基金the Natural Science Foundation of Hebei(B02020208088,H_(2)020206514)the S&T Program of Hebei(20544401D,20314401D,206Z4406G,21314402D,B2021208074,21344601D)the Tianjin Science and Technology Project(19YFSLQY00070)。
文摘Electrochemical reduction of CO_(2)(CO_(2)ER) to formate has been a promising route to produce value-added chemicals.Developing low-cost and efficient electrocatalysts with high product selectivity is still a grand challenge.Herein,a novel Ni nanoparticles-anchored CNT coated by mesoporous carbon with yolk-shell structure (CNT/Ni@mC) catalysis was designed for CO_(2)ER.Ni nanoparticles were confined in the cavity between CNT and mesoporous carbon shell and the confined space can be controlled by tuning the amount of silica precursor.The mesoporous carbon shell and confined space are beneficial to charge transmission during CO_(2)ER.In contrast to previous studies,the CNT/Ni@mC catalyst presents selectivity toward formate rather than CO.Electrochemical in situ attenuated total reflection Fourier transform infrared spectroscopy measurements indicate the presence of a COO* intermediate that converts to formate under CO_(2)ER conditions.The well-defined structural feature of the confined space of the Ni-based catalyst for selective CO_(2)ER to formate may facilitate in-depth mechanistic understandings on structural factors that affect CO_(2)ER performance.
