W<sup>6+</sup>-doped TiO<sub>2</sub> was prepared by sodium tungsten (VI) and titanium sulfate with sodium dodecyl sulfate as surfactant under microwave irradiation. The samples were characteri...W<sup>6+</sup>-doped TiO<sub>2</sub> was prepared by sodium tungsten (VI) and titanium sulfate with sodium dodecyl sulfate as surfactant under microwave irradiation. The samples were characterized by X-ray diffraction (XRD) and Scanning electron micrograph (SEM). The results showed that the as-prepared nanocomposite of inventory molar ratio of 2% calcined at 500°C for 2 h was anatase. The SEM showed that the majority of the catalyst was a relatively flake structure, and some fine particles attached to it. We also studied the photocatalytic activity of the as-prepared samples by using degradation of methyl orange. The factors including inventory molar ratio and concentration of W<sup>6+</sup>-doped, calcined temperature, amount of hydrogen peroxide and acidity of solution were investigated. When the catalyst was 1.0 g/L, pH was 2, C(H<sub>2</sub>O<sub>2</sub>) was 3 mL/L, the degradation rate of TiO<sub>2</sub> for methyl orange of 20 mg/L reached 79.63% in 40 min.展开更多
Nanocomposite of CdIn2S4 was synthesized by direct feeding microwave synthesis method, using indium nitrate, cadmium nitrate and thioacetamide as raw material, cetyltrimethyl ammonium bromide(CTAB) as surfactant. The ...Nanocomposite of CdIn2S4 was synthesized by direct feeding microwave synthesis method, using indium nitrate, cadmium nitrate and thioacetamide as raw material, cetyltrimethyl ammonium bromide(CTAB) as surfactant. The crystal structure, morphology and the optical property of as-prepared sample were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and Fluorescence spectra. The results showed that the as-prepared nanocomposite is hexagonal CdIn2S4. The SEM showed that the shape of these nanoparticles is irregular and looks like flake/sphere with some aggregation. The size of most of the aggregate is 100 to 300 nm. The photocatalytic activity of the as-prepared samples was studied by using degradation of methylene bule under visible light. The results show that the photocatalytic activity of CaIn2S4 photocatalyst was very well. When the catalyst was 1.0 g/L, C(H2O2) was 3 mL/L, after 120 min of the irradiation, the degradation rate of CdIn2S4 for methylene blue of 20 mg/L reached 86.06%.展开更多
Ce/BiVO4 nanocomposites photocatalyst was synthesized by direct feeding microwave synthesis method, using bismuth nitrate (Bi (NO3)3·5H2O), cerium?nitrate hexahydrate (Ce (NO3)3·6H2O) and ammonium metavanada...Ce/BiVO4 nanocomposites photocatalyst was synthesized by direct feeding microwave synthesis method, using bismuth nitrate (Bi (NO3)3·5H2O), cerium?nitrate hexahydrate (Ce (NO3)3·6H2O) and ammonium metavanadate (NH4VO3) as raw material and sodium dodecyl sulfate (SDS) as surfactant. The X-ray diffractometer (XRD) and the scanning electron microscopy (SEM) technology were used to characterize the Ce/BiVO4 nanocomposites. We investigated the photocatalytic activity of the as-prepared photocatalyst, and methyl orange was used as organic pollutant. The results show that the Ce/BiVO4 nanocomposite was a good photocatalyst under visible light. In 100 ml of 5 mg/L methylene orange solution, when the catalyst calcined at 673 K was 0.1 g, hydrogen peroxide was 0.5 ml, pH was 2.0, and the degradation ratio of catalyst for methylene orange reached 90.26% within 70 min.展开更多
In this paper, CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites were prepared by direct feeding microwave synthesis method with nine water iron nitrate (Fe(NO<sub>3</sub>)3&bull...In this paper, CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites were prepared by direct feeding microwave synthesis method with nine water iron nitrate (Fe(NO<sub>3</sub>)3•9H<sub>2</sub>O), cerium nitrate hexahydrate (Ce(NO<sub>3</sub>)3•6H<sub>2</sub>O) and ammonium metavanadate (NH<sub>4</sub>VO<sub>3</sub>) as raw material and Sodium Dodecyl Sulfate (SDS) as surfactant. Then X-Ray Diffractometer (XRD) and Scanning Electron Microscopy (SEM) were used to observe the CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites. SEM image showed that the as-prepared CeVO<sub>4</sub>/ FeVO<sub>4</sub> nanocomposites calcined at 773 Kis formated of small particles aggregation irregular sheet structure. We studied the photocatalytic activity of the as-prepared samples by using degradation of methyl orange in visible light. The results showed that the photocatalytic activity of CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites were very well. It found that when the catalyst calcined at 773 K was 0.10 g, and 0.5 mL hydrogen peroxide joined as well as, pH was 2.0, the degradation ratio of catalyst for methylene orange of 100 mL 5 mg/L reached 98.63% in 40 min.展开更多
Developing an efficient approach of transforming biomass waste to functional carbon-based electrode materials applied in supercapacitor offers an important and high value-added practical application due to the abundan...Developing an efficient approach of transforming biomass waste to functional carbon-based electrode materials applied in supercapacitor offers an important and high value-added practical application due to the abundance and considerable low price of biomass wastes.Herein,a hierarchical carbon functionalized with electrochemical-active oxygen-containing groups was fabricated by microwave treatment from the biomass waste of camellia oleifera.The obtained mesoporous carbon(MAC)owns nanosheet morphology,rich mesoporosity,large surface area(1726 m2/g)and very high oxygenic functionalities(16.2 wt%)with pseudocapacitive activity.Prepared electrode of supercapacitor and tested in 2.0 M H2 SO4,the MAC exhibits an obvious pseudocapacitive activity and achieved a superior supercapacitive performance to that of directly activated carbon(DAC-800)including high specific capacitance(367 F/g vs.298 F/g)and better rate performance(66%vs.44%).The symmetrical supercapacitor based on MAC shows a high capacity of275 F/g,large energy density of 9.55 Wh/kg(at power density of 478 W/kg)and excellent cycling stability with 99%capacitance retention after 10000 continuous charge-discharge,endowing the obtained MAC a promising functional material for electrochemical energy storage.展开更多
Three 1 D chain coordination polymers [Ln(pydc)2(H2 O)2]n·n Him(Ln = Dy(1), Gd(2), Sm(3), H2 pydc = pyridine-2,5-dicarboxylic acid, Im = imidazole), were solvothermally synthesized by the reaction of pyridine-2,5...Three 1 D chain coordination polymers [Ln(pydc)2(H2 O)2]n·n Him(Ln = Dy(1), Gd(2), Sm(3), H2 pydc = pyridine-2,5-dicarboxylic acid, Im = imidazole), were solvothermally synthesized by the reaction of pyridine-2,5-dicarboxylic acid(H2 pydc), Ln(Ⅲ) salts and imidazole. They have been characterized by X-ray single-crystal diffraction, IR spectra, TGA analysis and elemental analysis. Structural analyses revealed that complexes 1~3 have similar 1 D chain structures and belong to P1 space group. It is noteworthy that complexes 1~3 exhibited excellent thermal stability and no weightlessness below 117 ℃. Meanwhile, 1 and 3 show characteristic fluorescence of corresponding lanthanide metal ions in solid state at room temperature.展开更多
Barium tungstate of homogeneous double cone structure was synthesized by microwave synthesis method with sodium tungstate, barium nitrate as raw materials, polyethylene glycol (PEG2000) as surfactant. The as-prepared ...Barium tungstate of homogeneous double cone structure was synthesized by microwave synthesis method with sodium tungstate, barium nitrate as raw materials, polyethylene glycol (PEG2000) as surfactant. The as-prepared sample was characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and photoluminescence spectrum (PL). The XRD Pattern showed that the samples are scheelite structure of BaWO4. The SEM image showed that the majority of as-prepared sample is a double cone structure, and some particles are attached to it. The length of most of the double cone is 10 μm. PL spectra showed that as-prepared sample had strong luminescence properties, and it had purity green emission at 495 nm and 521 nm. The effects of different surface active agent on the luminescence properties were studied. The results showed that when PEG2000 is as surfactant, the luminescence intensity of as-prepared sample was maximum.展开更多
In this paper, using calcium chloride and sodium molybdate as raw material, polyethylene glycol (PEG2000) as surfactant, the nanocomposites of CaMoO4: Eu3+ were prepared by a direct feeding microwave synthesis method....In this paper, using calcium chloride and sodium molybdate as raw material, polyethylene glycol (PEG2000) as surfactant, the nanocomposites of CaMoO4: Eu3+ were prepared by a direct feeding microwave synthesis method. The as-prepared sample was characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and photoluminescence spectrum (PL). The XRD Pattern showed that the samples are scheelite structure of CaMoO4. The SEM image showed that the majority of as-prepared sample is a relatively flake structure, and some fine particles attached to it. PL spectra showed that as-prepared samples have strong luminescence properties;it had purity red emission at 615 nm. The effects of different Eu3+ ions doping amount and surface active agent on the photoluminescence properties were studied. The results showed that when the molar ratio of Eu3+ was 0.10, PEG2000 as surfactant, the luminescence intensity of as-prepared sample was maximum.展开更多
The title complex [HSr3(pda)3(H2O)3Cl]n(1, H2pda = pyridine-2,6-dicarboxylic acid) has been prepared under two-step solvothermal conditions. It has been characterized by X-ray single-crystal diffraction, IR, TGA...The title complex [HSr3(pda)3(H2O)3Cl]n(1, H2pda = pyridine-2,6-dicarboxylic acid) has been prepared under two-step solvothermal conditions. It has been characterized by X-ray single-crystal diffraction, IR, TGA-DSC and elemental analysis. The crystal belongs to the trigonal system, space group R-3 with a = 14.484(2), b = 14.484(2), c = 21.970(4) A, γ = 120 o, V = 3991.4(11) A3, C(21)H(16)ClN3O(1)5Sr3, Mr = 848.68, Z = 6, Dc = 2.118 g/cm^3, μ = 6.175 mm-1, F(000) = 2484, the final R = 0.0457 and w R = 0.1139. This complex possesses a 3-D structure constructed from [HSr3(pda)3(H2O)3Cl]2 units and connected by coordinated carboxylate groups of pda2-ligands. The topology symbol of this network is(4^(12)6~3). Luminescent property of the title complex has been investigated at room temperature.展开更多
Understanding the mechanism of the interfacial reaction between the cathode material and the electrolyte is a significant work because the interfacial reaction is an important factor affecting the stability,capacity,a...Understanding the mechanism of the interfacial reaction between the cathode material and the electrolyte is a significant work because the interfacial reaction is an important factor affecting the stability,capacity,and cycling performance of Li-ion batteries.In this work,spin-polarized density functional theory calculations with on-site Coulomb energy have been employed to study the adsorption of electrolyte components propylene carbonate(PC)on the LiMn2O4(100)surface.The findings show that the PC molecule prefers to interact with the Mn atom on the LiMn2O4(100)surface via the carbonyl oxygen(Oc),with the adsorption energy of−1.16 eV,which is an exothermic reaction.As the adsorption of organic molecule PC increases the Mn atoms coordination with O atoms on the(100)surface,the Mn3+ions on the surface lose charge and the reactivity is substantially decreased,which improves the stability of the surface and benefits the cycling performance.展开更多
Developing carbon-based supercapacitors with high rate capability is of great importance to meet the emerging demands for devices that requires high energy density as well as high power density.However,it is hard to f...Developing carbon-based supercapacitors with high rate capability is of great importance to meet the emerging demands for devices that requires high energy density as well as high power density.However,it is hard to fabricate a nanocarbon with high electro-active surface area meanwhile maintaining superior conductivity to ensure the high rate capability since excellent conductivity is usually realized by high temperature graphitization,which would lead to the structural collapse and sintering resulting in low surface area.Herein,we reported a highly porous graphitic carbon nanosheet with an unprecedented rate capability of 98%of its initial capacitance from 0.5 to 50 A/g for ultrahigh-rate supercapacitive energy storage.These hierarchical mesoporous carbon nanosheets(HMCN)were fabricated by a template induced catalytic graphitization approach,in which sheet-like Mg(OH)_(2) was employed as catalytic template in situ catalytically polymerizing of catechol and formaldehyde and catalytically graphitizing of the formed carbon skeleton.Upon the co-effect of template(avoiding the sintering)and the deoxygenation(creating the pores)during the high temperature graphitization process,the obtained HMCN material possesses nanosheet morphology with highly porous graphitic microstructure rich in mesoporosity,large in surface area(2316 m^(2)/g),large in pore volume(3.58 cm^(3)/g)and excellent in conductivity(109.8 S/cm).In 1.0 M TEABF_(4)/AN,HMCN exhibits superior supercapacitive performance including large energy density of 52.2 Wh/kg at high power density of 118 k W/kg,long-cycling stability and excellent rate capability,making HMCN a promising electrode material for supercapacitor devices.展开更多
The growth of a Ni(OH)2 coating on conductive carbon substrates is an efficient way to address issues related to their poor conductivity in electrochemical capacitor applications. However, the direct growth of nicke...The growth of a Ni(OH)2 coating on conductive carbon substrates is an efficient way to address issues related to their poor conductivity in electrochemical capacitor applications. However, the direct growth of nickel hydroxide coatings on a carbon substrate is challenging, because the surfaces of these systems are not compatible and a preoxidation treatment of the conductive carbon substrate is usually required. Herein, we present a facile preoxidation-free approach to fabricate a uniform Ni(OH)2 coating on carbon nanosheets (CNs) by an ion-exchange reaction to achieve the in situ transformation of a MgO/C composite to a Ni(OH)2/C one. The obtained Ni(OH)2/CNs hybrids possess nanosheet morphology, a large surface area (278 m2/g), and homogeneous elemental distributions. When employed as supercapacitors in a three-electrode configuration, the Ni(OH)JCNs hybrid achieves a large capacitance of 2,218 F/g at a current density of 1.0 A/g. Moreover, asymmetric supercapacitors fabricated with the Ni(OH)2/CNs hybrid exhibit superior supercapacitive performances, with a large capacity of 198 F/g, and high energy density of 56.7 Wh/kg at a power density of 4.0 kW/kg. They show excellent cycling stability with 93% capacity retention after 10,000 cycles, making the Ni(OH)2/CNs hybrid a promising candidate for practical applications in supercapacitor devices.展开更多
Nitrogen doping is usually adopted in carbon based supercapacitor to enhance its relatively low energy density by providing extra pseudocapacity.However,the improvement of energy density is normally limited because th...Nitrogen doping is usually adopted in carbon based supercapacitor to enhance its relatively low energy density by providing extra pseudocapacity.However,the improvement of energy density is normally limited because the content of the introduced nitrogen species is not high and meanwhile only part of them is electrochemically active.Herein,we designed and fabricated a class of hierarchical nitrogen-rich porous carbons(HNPCs)possessing not only very high nitrogen content(up to 21.7 atom%)but also fully electrochemically active nitrogen species(i.e.,pyridinic N,pyrrolic N and oxidized N).Especially,in the synthesis of HNPCs,graphitic carbon nitride(g-C3N4)was used in situ not only as a nitrogen source but also as a catalyst to facilitate the polymerization of phenol and formaldehyde(as carbon precursor)and as a template to create the hierarchical porous structure.As electrodes for aqueous symmetric supercapacitor,the HNPCs with full faradaic-active nitrogen functionalities exhibit excellent supercapacitor performance:high energy density of 36.8 Wh/kg at 2.0 kW/kg(maintaining 25.7 Wh/kg at 38 kW/kg),superior rate capability with 78%capacitance retention from 1.0 to 20 A/g and excellent cycling stability with over95%capacitance retention after 10000 cycles,indicating their promising application potential in electrochemical energy storage.This novel carbon material with high-content and full electrochemically active nitrogen species may find extensive potential applications in the energy storage/conversion,catalysis,adsorption,and so on.展开更多
Development of high-performance and cost-effective catalysts for electrocatalytic hydrogen evolution reaction(HER)play crucial role in the growing hydrogen economy.Recently,the atomically dispersed metal catalysts hav...Development of high-performance and cost-effective catalysts for electrocatalytic hydrogen evolution reaction(HER)play crucial role in the growing hydrogen economy.Recently,the atomically dispersed metal catalysts have attracted increasing attention due to their ultimate atom utilization and great potential for highly cost-effective and high-efficiency HER electrocatalyst.Herein,we propose a hightemperature treatment strategy to furtherly improve the HER performance of atomically dispersed Ptbased catalyst.Interestingly,after appropriate high-temperature treatment on the atomically dispersed Pt0.8@CN,the Pt species on the designed N-doped porous carbon substrate with rich defect sites can be re-dispersed to single atom state with new coordination environment.The obtained Pt0.8@CN-1000 shows superior HER performance with overpotential of 13 m V at 10 m A cm^(-2)and mass activity of 11,284 m A/mgPtat-0.1 V,much higher than that of the pristine Pt0.8@CN and commercial Pt/C catalyst.The experimental and theoretical investigations indicate that the high-temperature treatment induces the restructuring of coordination environment and then the optimized Pt electronic state leads to the enhanced HER performances.This work affords new strategy and insights to develop the atomically dispersed high-efficiency catalysts.展开更多
Synthesis of functionalized mesoporous carbon by an easy-accessed method is of great importance towards its practical applications.Herein,an evaporation induced self-assembly/carbonization(EISAC)method was developed...Synthesis of functionalized mesoporous carbon by an easy-accessed method is of great importance towards its practical applications.Herein,an evaporation induced self-assembly/carbonization(EISAC)method was developed and applied to the synthesis of sulfonic acid group functionalized mesoporous carbon(SMC).The final mesoporous carbon obtained by EISAC method possesses wormlike mesoporous structure,uniform pore size(3.6 nm),large surface area of 735 m^2/g,graphitic pore walls and rich sulfonic acid group.Moreover,the resultant mesoporous carbon achieves a superior electrochemical capacitive performances(216 F/g) to phenolic resin derived mesoporous carbon(OMC,152 F/g) and commercial activated carbon(AC,119 F/g).展开更多
The health safety of methylglyoxal(MGO) has been recognized as a key issue owing to its ultra-high reactivity toward some key biomolecules such as amino acids, proteins, DNA, sulfhydryl-and basic nitrogencontaining co...The health safety of methylglyoxal(MGO) has been recognized as a key issue owing to its ultra-high reactivity toward some key biomolecules such as amino acids, proteins, DNA, sulfhydryl-and basic nitrogencontaining compounds, including amino-bearing neurotransmitters. In this review, we have summarized the endoand exogenous sources of MGO and its accumulation inside the body due to high intake, abnormal glucose metabolism and or malfunctioning glyoxalases, and review the debate concerning the adverse functionality of MGO ingested from foods. Higher than normal concentrations of MGO in the circulatory system and tissues have been found to be closely associated with the production of advanced glycation end products(AGEs), increased oxidative stress, elevated inflammation and RAGE(AGE receptors) activity, which subsequently progresses to a pathological stage of human health, such as diabetes complications, cancer, cardiovascular and degenerative diseases. Having illustrated the mechanisms of MGO trapping in vivo, we advocate the development of efficient and efficacious MGO scavengers, either assisting or enhancing the activity of endogenous glyoxalases to facilitate MGO removal, or providing phytochemicals and functional foods containing them, or pharmaceuticals to irreversibly bind MGO and thus form MGO-complexes that are cleared from the body.展开更多
Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient ele...Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient elec-trons.Here,we report the modulation of electrode/elec-trolyte interface to yield excellent rate performance by creating cross-linked conducting carbon network in LiFePO_(4)/C cathode material.Such conducting networks inhibit agglomeration and growth of LiFePO_(4)/C primary particles and hence lead to a short Li^(+)diffusion pathway.Furthermore,it also offers fast electron transmission rate and efficient electron for Li storage in the LiFePO_(4)sheath.The LiFePO_(4)/C with carbon nanotubes(CNTs)delivers a discharge capacity of 150.9 mAh·g^(-1) at 0.1C(initial Coulombic efficiency of 96.4%)and an enhanced rate capability(97.2 mAh·g^(-1) at 20.0C).Importantly,it exhi-bits a high cycle stability with a capacity retention of 90.3%even after 800 cycles at 5.0C(0.85 A·g^(-1)).This proposed interface design can be applied to a variety of battery electrodes that face challenges in electrical contact and ion transport.展开更多
Nitroxoline is a wide spectrum antibacterial and is one of the most important urinary antiseptics.The interaction between nitroxoline and human serum albumin(HSA)has been investigated systematically by fluorescence sp...Nitroxoline is a wide spectrum antibacterial and is one of the most important urinary antiseptics.The interaction between nitroxoline and human serum albumin(HSA)has been investigated systematically by fluorescence spectroscopy,synchronous fluorescence,three-dimensional fluorescence,CD spectroscopy and UV-Vis absorption spectroscopy.The results indicated that the quenching of HSA by nitroxoline was static.The corresponding thermodynamic parameters △H,△S and △G calculated according to van’t Hoff equation revealed that the intermolecular forces acting between nitroxoline and HSA were mainly hydrogen bonding and van der Waals forces.The conformational changes in the interaction were studied by synchronous fluorescence,CD spectroscopy and three-dimensional fluorescence spectra which showed changes in the microenvironment and conformation of HSA.展开更多
文摘W<sup>6+</sup>-doped TiO<sub>2</sub> was prepared by sodium tungsten (VI) and titanium sulfate with sodium dodecyl sulfate as surfactant under microwave irradiation. The samples were characterized by X-ray diffraction (XRD) and Scanning electron micrograph (SEM). The results showed that the as-prepared nanocomposite of inventory molar ratio of 2% calcined at 500°C for 2 h was anatase. The SEM showed that the majority of the catalyst was a relatively flake structure, and some fine particles attached to it. We also studied the photocatalytic activity of the as-prepared samples by using degradation of methyl orange. The factors including inventory molar ratio and concentration of W<sup>6+</sup>-doped, calcined temperature, amount of hydrogen peroxide and acidity of solution were investigated. When the catalyst was 1.0 g/L, pH was 2, C(H<sub>2</sub>O<sub>2</sub>) was 3 mL/L, the degradation rate of TiO<sub>2</sub> for methyl orange of 20 mg/L reached 79.63% in 40 min.
文摘Nanocomposite of CdIn2S4 was synthesized by direct feeding microwave synthesis method, using indium nitrate, cadmium nitrate and thioacetamide as raw material, cetyltrimethyl ammonium bromide(CTAB) as surfactant. The crystal structure, morphology and the optical property of as-prepared sample were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and Fluorescence spectra. The results showed that the as-prepared nanocomposite is hexagonal CdIn2S4. The SEM showed that the shape of these nanoparticles is irregular and looks like flake/sphere with some aggregation. The size of most of the aggregate is 100 to 300 nm. The photocatalytic activity of the as-prepared samples was studied by using degradation of methylene bule under visible light. The results show that the photocatalytic activity of CaIn2S4 photocatalyst was very well. When the catalyst was 1.0 g/L, C(H2O2) was 3 mL/L, after 120 min of the irradiation, the degradation rate of CdIn2S4 for methylene blue of 20 mg/L reached 86.06%.
文摘Ce/BiVO4 nanocomposites photocatalyst was synthesized by direct feeding microwave synthesis method, using bismuth nitrate (Bi (NO3)3·5H2O), cerium?nitrate hexahydrate (Ce (NO3)3·6H2O) and ammonium metavanadate (NH4VO3) as raw material and sodium dodecyl sulfate (SDS) as surfactant. The X-ray diffractometer (XRD) and the scanning electron microscopy (SEM) technology were used to characterize the Ce/BiVO4 nanocomposites. We investigated the photocatalytic activity of the as-prepared photocatalyst, and methyl orange was used as organic pollutant. The results show that the Ce/BiVO4 nanocomposite was a good photocatalyst under visible light. In 100 ml of 5 mg/L methylene orange solution, when the catalyst calcined at 673 K was 0.1 g, hydrogen peroxide was 0.5 ml, pH was 2.0, and the degradation ratio of catalyst for methylene orange reached 90.26% within 70 min.
文摘In this paper, CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites were prepared by direct feeding microwave synthesis method with nine water iron nitrate (Fe(NO<sub>3</sub>)3•9H<sub>2</sub>O), cerium nitrate hexahydrate (Ce(NO<sub>3</sub>)3•6H<sub>2</sub>O) and ammonium metavanadate (NH<sub>4</sub>VO<sub>3</sub>) as raw material and Sodium Dodecyl Sulfate (SDS) as surfactant. Then X-Ray Diffractometer (XRD) and Scanning Electron Microscopy (SEM) were used to observe the CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites. SEM image showed that the as-prepared CeVO<sub>4</sub>/ FeVO<sub>4</sub> nanocomposites calcined at 773 Kis formated of small particles aggregation irregular sheet structure. We studied the photocatalytic activity of the as-prepared samples by using degradation of methyl orange in visible light. The results showed that the photocatalytic activity of CeVO<sub>4</sub>/FeVO<sub>4</sub> nanocomposites were very well. It found that when the catalyst calcined at 773 K was 0.10 g, and 0.5 mL hydrogen peroxide joined as well as, pH was 2.0, the degradation ratio of catalyst for methylene orange of 100 mL 5 mg/L reached 98.63% in 40 min.
基金financially supported by the National Key Technology R&D Program of China(2017YFB0310704)the National Natural Science Foundation of China(21773112 and 21173119)the Fundamental Research Funds for the Central Universities
文摘Developing an efficient approach of transforming biomass waste to functional carbon-based electrode materials applied in supercapacitor offers an important and high value-added practical application due to the abundance and considerable low price of biomass wastes.Herein,a hierarchical carbon functionalized with electrochemical-active oxygen-containing groups was fabricated by microwave treatment from the biomass waste of camellia oleifera.The obtained mesoporous carbon(MAC)owns nanosheet morphology,rich mesoporosity,large surface area(1726 m2/g)and very high oxygenic functionalities(16.2 wt%)with pseudocapacitive activity.Prepared electrode of supercapacitor and tested in 2.0 M H2 SO4,the MAC exhibits an obvious pseudocapacitive activity and achieved a superior supercapacitive performance to that of directly activated carbon(DAC-800)including high specific capacitance(367 F/g vs.298 F/g)and better rate performance(66%vs.44%).The symmetrical supercapacitor based on MAC shows a high capacity of275 F/g,large energy density of 9.55 Wh/kg(at power density of 478 W/kg)and excellent cycling stability with 99%capacitance retention after 10000 continuous charge-discharge,endowing the obtained MAC a promising functional material for electrochemical energy storage.
基金supported by the Natural Science Foundation of China(No.21501061)the Natural Science Foundation of Hubei Province(No.2016CFB147)+2 种基金Foundation of Hubei Educational Committee(D20172904)the Technology Innovation Team Program of Hubei Provincial Colleges and Universities(T201514)Doctoral Fund Project of Huanggang Normal University(No.2015001803)
文摘Three 1 D chain coordination polymers [Ln(pydc)2(H2 O)2]n·n Him(Ln = Dy(1), Gd(2), Sm(3), H2 pydc = pyridine-2,5-dicarboxylic acid, Im = imidazole), were solvothermally synthesized by the reaction of pyridine-2,5-dicarboxylic acid(H2 pydc), Ln(Ⅲ) salts and imidazole. They have been characterized by X-ray single-crystal diffraction, IR spectra, TGA analysis and elemental analysis. Structural analyses revealed that complexes 1~3 have similar 1 D chain structures and belong to P1 space group. It is noteworthy that complexes 1~3 exhibited excellent thermal stability and no weightlessness below 117 ℃. Meanwhile, 1 and 3 show characteristic fluorescence of corresponding lanthanide metal ions in solid state at room temperature.
文摘Barium tungstate of homogeneous double cone structure was synthesized by microwave synthesis method with sodium tungstate, barium nitrate as raw materials, polyethylene glycol (PEG2000) as surfactant. The as-prepared sample was characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and photoluminescence spectrum (PL). The XRD Pattern showed that the samples are scheelite structure of BaWO4. The SEM image showed that the majority of as-prepared sample is a double cone structure, and some particles are attached to it. The length of most of the double cone is 10 μm. PL spectra showed that as-prepared sample had strong luminescence properties, and it had purity green emission at 495 nm and 521 nm. The effects of different surface active agent on the luminescence properties were studied. The results showed that when PEG2000 is as surfactant, the luminescence intensity of as-prepared sample was maximum.
文摘In this paper, using calcium chloride and sodium molybdate as raw material, polyethylene glycol (PEG2000) as surfactant, the nanocomposites of CaMoO4: Eu3+ were prepared by a direct feeding microwave synthesis method. The as-prepared sample was characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and photoluminescence spectrum (PL). The XRD Pattern showed that the samples are scheelite structure of CaMoO4. The SEM image showed that the majority of as-prepared sample is a relatively flake structure, and some fine particles attached to it. PL spectra showed that as-prepared samples have strong luminescence properties;it had purity red emission at 615 nm. The effects of different Eu3+ ions doping amount and surface active agent on the photoluminescence properties were studied. The results showed that when the molar ratio of Eu3+ was 0.10, PEG2000 as surfactant, the luminescence intensity of as-prepared sample was maximum.
基金supported by the National Natural Science Foundation of China(No.21501061)Natural Science Foundation of Hubei Province(No.2016CFB147)Doctoral Fund Project of Huanggang Normal University(No.2015001803)
文摘The title complex [HSr3(pda)3(H2O)3Cl]n(1, H2pda = pyridine-2,6-dicarboxylic acid) has been prepared under two-step solvothermal conditions. It has been characterized by X-ray single-crystal diffraction, IR, TGA-DSC and elemental analysis. The crystal belongs to the trigonal system, space group R-3 with a = 14.484(2), b = 14.484(2), c = 21.970(4) A, γ = 120 o, V = 3991.4(11) A3, C(21)H(16)ClN3O(1)5Sr3, Mr = 848.68, Z = 6, Dc = 2.118 g/cm^3, μ = 6.175 mm-1, F(000) = 2484, the final R = 0.0457 and w R = 0.1139. This complex possesses a 3-D structure constructed from [HSr3(pda)3(H2O)3Cl]2 units and connected by coordinated carboxylate groups of pda2-ligands. The topology symbol of this network is(4^(12)6~3). Luminescent property of the title complex has been investigated at room temperature.
基金Project supported by the National Natural Science Foundation of China(Grant No.51962010).
文摘Understanding the mechanism of the interfacial reaction between the cathode material and the electrolyte is a significant work because the interfacial reaction is an important factor affecting the stability,capacity,and cycling performance of Li-ion batteries.In this work,spin-polarized density functional theory calculations with on-site Coulomb energy have been employed to study the adsorption of electrolyte components propylene carbonate(PC)on the LiMn2O4(100)surface.The findings show that the PC molecule prefers to interact with the Mn atom on the LiMn2O4(100)surface via the carbonyl oxygen(Oc),with the adsorption energy of−1.16 eV,which is an exothermic reaction.As the adsorption of organic molecule PC increases the Mn atoms coordination with O atoms on the(100)surface,the Mn3+ions on the surface lose charge and the reactivity is substantially decreased,which improves the stability of the surface and benefits the cycling performance.
基金financially supported by the National Science Foundation of China(22172073 and 21773112)the Fundamental Research Funds for the Central Universitiesthe Science and Technology Innovation Team Plan for the youths in universities of Hubei province(T2020021)。
文摘Developing carbon-based supercapacitors with high rate capability is of great importance to meet the emerging demands for devices that requires high energy density as well as high power density.However,it is hard to fabricate a nanocarbon with high electro-active surface area meanwhile maintaining superior conductivity to ensure the high rate capability since excellent conductivity is usually realized by high temperature graphitization,which would lead to the structural collapse and sintering resulting in low surface area.Herein,we reported a highly porous graphitic carbon nanosheet with an unprecedented rate capability of 98%of its initial capacitance from 0.5 to 50 A/g for ultrahigh-rate supercapacitive energy storage.These hierarchical mesoporous carbon nanosheets(HMCN)were fabricated by a template induced catalytic graphitization approach,in which sheet-like Mg(OH)_(2) was employed as catalytic template in situ catalytically polymerizing of catechol and formaldehyde and catalytically graphitizing of the formed carbon skeleton.Upon the co-effect of template(avoiding the sintering)and the deoxygenation(creating the pores)during the high temperature graphitization process,the obtained HMCN material possesses nanosheet morphology with highly porous graphitic microstructure rich in mesoporosity,large in surface area(2316 m^(2)/g),large in pore volume(3.58 cm^(3)/g)and excellent in conductivity(109.8 S/cm).In 1.0 M TEABF_(4)/AN,HMCN exhibits superior supercapacitive performance including large energy density of 52.2 Wh/kg at high power density of 118 k W/kg,long-cycling stability and excellent rate capability,making HMCN a promising electrode material for supercapacitor devices.
文摘The growth of a Ni(OH)2 coating on conductive carbon substrates is an efficient way to address issues related to their poor conductivity in electrochemical capacitor applications. However, the direct growth of nickel hydroxide coatings on a carbon substrate is challenging, because the surfaces of these systems are not compatible and a preoxidation treatment of the conductive carbon substrate is usually required. Herein, we present a facile preoxidation-free approach to fabricate a uniform Ni(OH)2 coating on carbon nanosheets (CNs) by an ion-exchange reaction to achieve the in situ transformation of a MgO/C composite to a Ni(OH)2/C one. The obtained Ni(OH)2/CNs hybrids possess nanosheet morphology, a large surface area (278 m2/g), and homogeneous elemental distributions. When employed as supercapacitors in a three-electrode configuration, the Ni(OH)JCNs hybrid achieves a large capacitance of 2,218 F/g at a current density of 1.0 A/g. Moreover, asymmetric supercapacitors fabricated with the Ni(OH)2/CNs hybrid exhibit superior supercapacitive performances, with a large capacity of 198 F/g, and high energy density of 56.7 Wh/kg at a power density of 4.0 kW/kg. They show excellent cycling stability with 93% capacity retention after 10,000 cycles, making the Ni(OH)2/CNs hybrid a promising candidate for practical applications in supercapacitor devices.
基金supported by the National Natural Science Foundation of China(21773112,21173119,and 21273109)the Natural Science Foundation of Hubei Province(2019CFB626)+1 种基金the Initial Research Fund(2042019023)the Cultivation Fund(204201814003)of Huanggang Normal University。
文摘Nitrogen doping is usually adopted in carbon based supercapacitor to enhance its relatively low energy density by providing extra pseudocapacity.However,the improvement of energy density is normally limited because the content of the introduced nitrogen species is not high and meanwhile only part of them is electrochemically active.Herein,we designed and fabricated a class of hierarchical nitrogen-rich porous carbons(HNPCs)possessing not only very high nitrogen content(up to 21.7 atom%)but also fully electrochemically active nitrogen species(i.e.,pyridinic N,pyrrolic N and oxidized N).Especially,in the synthesis of HNPCs,graphitic carbon nitride(g-C3N4)was used in situ not only as a nitrogen source but also as a catalyst to facilitate the polymerization of phenol and formaldehyde(as carbon precursor)and as a template to create the hierarchical porous structure.As electrodes for aqueous symmetric supercapacitor,the HNPCs with full faradaic-active nitrogen functionalities exhibit excellent supercapacitor performance:high energy density of 36.8 Wh/kg at 2.0 kW/kg(maintaining 25.7 Wh/kg at 38 kW/kg),superior rate capability with 78%capacitance retention from 1.0 to 20 A/g and excellent cycling stability with over95%capacitance retention after 10000 cycles,indicating their promising application potential in electrochemical energy storage.This novel carbon material with high-content and full electrochemically active nitrogen species may find extensive potential applications in the energy storage/conversion,catalysis,adsorption,and so on.
基金financially supported by the National Science Foundation of China(21773112,21173119,and 21273109)the National Key Technology R&D Program of China(2017YFB0310704)the Fundamental Research Funds for the Central Universities and the Hubei Key Laboratory for Processing and Application of Catalytic Materials(CH201401)。
文摘Development of high-performance and cost-effective catalysts for electrocatalytic hydrogen evolution reaction(HER)play crucial role in the growing hydrogen economy.Recently,the atomically dispersed metal catalysts have attracted increasing attention due to their ultimate atom utilization and great potential for highly cost-effective and high-efficiency HER electrocatalyst.Herein,we propose a hightemperature treatment strategy to furtherly improve the HER performance of atomically dispersed Ptbased catalyst.Interestingly,after appropriate high-temperature treatment on the atomically dispersed Pt0.8@CN,the Pt species on the designed N-doped porous carbon substrate with rich defect sites can be re-dispersed to single atom state with new coordination environment.The obtained Pt0.8@CN-1000 shows superior HER performance with overpotential of 13 m V at 10 m A cm^(-2)and mass activity of 11,284 m A/mgPtat-0.1 V,much higher than that of the pristine Pt0.8@CN and commercial Pt/C catalyst.The experimental and theoretical investigations indicate that the high-temperature treatment induces the restructuring of coordination environment and then the optimized Pt electronic state leads to the enhanced HER performances.This work affords new strategy and insights to develop the atomically dispersed high-efficiency catalysts.
基金supported by the Ministry of Science and Technology of China(No.2009CB623504)the National Science Foundation of China(Nos.20773062,20773063,21173119,and21273109)the Fundamental Research Funds for the Central Universities
文摘Synthesis of functionalized mesoporous carbon by an easy-accessed method is of great importance towards its practical applications.Herein,an evaporation induced self-assembly/carbonization(EISAC)method was developed and applied to the synthesis of sulfonic acid group functionalized mesoporous carbon(SMC).The final mesoporous carbon obtained by EISAC method possesses wormlike mesoporous structure,uniform pore size(3.6 nm),large surface area of 735 m^2/g,graphitic pore walls and rich sulfonic acid group.Moreover,the resultant mesoporous carbon achieves a superior electrochemical capacitive performances(216 F/g) to phenolic resin derived mesoporous carbon(OMC,152 F/g) and commercial activated carbon(AC,119 F/g).
基金supported by the USDA National Institute of Food and Agriculture, Hatch project 1007898
文摘The health safety of methylglyoxal(MGO) has been recognized as a key issue owing to its ultra-high reactivity toward some key biomolecules such as amino acids, proteins, DNA, sulfhydryl-and basic nitrogencontaining compounds, including amino-bearing neurotransmitters. In this review, we have summarized the endoand exogenous sources of MGO and its accumulation inside the body due to high intake, abnormal glucose metabolism and or malfunctioning glyoxalases, and review the debate concerning the adverse functionality of MGO ingested from foods. Higher than normal concentrations of MGO in the circulatory system and tissues have been found to be closely associated with the production of advanced glycation end products(AGEs), increased oxidative stress, elevated inflammation and RAGE(AGE receptors) activity, which subsequently progresses to a pathological stage of human health, such as diabetes complications, cancer, cardiovascular and degenerative diseases. Having illustrated the mechanisms of MGO trapping in vivo, we advocate the development of efficient and efficacious MGO scavengers, either assisting or enhancing the activity of endogenous glyoxalases to facilitate MGO removal, or providing phytochemicals and functional foods containing them, or pharmaceuticals to irreversibly bind MGO and thus form MGO-complexes that are cleared from the body.
基金financially supported by the National Natural Science Foundation of China (Nos. 51902108, 51762006 and 51774100)Guangxi Innovation Driven Development Subject (No. GUIKE AA19182020)+2 种基金Guangxi Natural Science Foundation (Nos. 2018GXNSFBA138002 and 2021GXNSFDA075 012)Guangxi Technology Base and Talent Subject (No. GUIKE AD18126001)Special Fund for Guangxi Distinguished Expert。
文摘Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient elec-trons.Here,we report the modulation of electrode/elec-trolyte interface to yield excellent rate performance by creating cross-linked conducting carbon network in LiFePO_(4)/C cathode material.Such conducting networks inhibit agglomeration and growth of LiFePO_(4)/C primary particles and hence lead to a short Li^(+)diffusion pathway.Furthermore,it also offers fast electron transmission rate and efficient electron for Li storage in the LiFePO_(4)sheath.The LiFePO_(4)/C with carbon nanotubes(CNTs)delivers a discharge capacity of 150.9 mAh·g^(-1) at 0.1C(initial Coulombic efficiency of 96.4%)and an enhanced rate capability(97.2 mAh·g^(-1) at 20.0C).Importantly,it exhi-bits a high cycle stability with a capacity retention of 90.3%even after 800 cycles at 5.0C(0.85 A·g^(-1)).This proposed interface design can be applied to a variety of battery electrodes that face challenges in electrical contact and ion transport.
基金financially supported by the National Science Fund for Distinguished Young Scholars of China(21225313)the National Natural Science Foundation of China(21303126)+2 种基金Program for Changjiang Scholars and Innovative Research Team in University(IRT1030)Foundation of Hubei Educational Committee(Q20132901)Youth Science Foundation of Huanggang Normal University(2013023903)
文摘Nitroxoline is a wide spectrum antibacterial and is one of the most important urinary antiseptics.The interaction between nitroxoline and human serum albumin(HSA)has been investigated systematically by fluorescence spectroscopy,synchronous fluorescence,three-dimensional fluorescence,CD spectroscopy and UV-Vis absorption spectroscopy.The results indicated that the quenching of HSA by nitroxoline was static.The corresponding thermodynamic parameters △H,△S and △G calculated according to van’t Hoff equation revealed that the intermolecular forces acting between nitroxoline and HSA were mainly hydrogen bonding and van der Waals forces.The conformational changes in the interaction were studied by synchronous fluorescence,CD spectroscopy and three-dimensional fluorescence spectra which showed changes in the microenvironment and conformation of HSA.