Monodispersed microsized copper oxalate particles were prepared in a segmented continuous flow tube reactor, and the effect of the main parameters such as organic additive agent, initial copper ions concentration, res...Monodispersed microsized copper oxalate particles were prepared in a segmented continuous flow tube reactor, and the effect of the main parameters such as organic additive agent, initial copper ions concentration, residence time, and segmented media on the final products were investigated experimentally. The obtained copper oxalate microsized particles were disc-like in the presence of citrate ligand,which was the shape inducer for the precipitated copper oxalate. Thermodynamic equilibrium diagrams of the Cu(Ⅱ)-oxalate-H_2O,Cu(Ⅱ)-oxalate-citrate-H_2O, and Cu(Ⅱ)-oxalate-EDTA-H_2O solution systems were drawn to estimate the possible copper species under the experimental conditions and to explain the formation mechanisms of copper oxalate particles in the segmented fluidic reactor. Both theoretical and experimental results indicated that the presence of chelating reagents such as citrate and EDTA had distinct effect on the evolution of particle shape. Air and kerosene were tested as media for the fluidic flow segmentation, and the latter was verified to better promote the growth of copper oxalate particles. The present study provides an easy method to prepare monodispersed copper oxalate microsized particles in a continuous scaling-up way, which can be utilized to prepare the precursor material for conductive inks.展开更多
Developing efficient and low-cost electrocatalysts is essential for the electroreduction of N_(2) to NH_(3).Here,highly monodispersed MoO_(3) clusters loaded on a coral-like CeO_(x)compound with abundant oxygen vacanc...Developing efficient and low-cost electrocatalysts is essential for the electroreduction of N_(2) to NH_(3).Here,highly monodispersed MoO_(3) clusters loaded on a coral-like CeO_(x)compound with abundant oxygen vacancies are successfully prepared by an impregnation-reduction method.The MoO_(3) clusters with small sizes of 2.6±0.5 nm are induced and anchored by the oxygen vacancies of CeO_(x),resulting in excellent nitrogen reduction reaction(NRR)performance.Additionally,the synergistic effects between MoO_(3) and CeO_(x)lead to a further improvement of the electrochemical performance.The as-prepared MoO_(3)-CeO_(x)catalyst shows an NH_(3) yield rate of 32.2 μg h^(-1) mg^(-1) cat and a faradaic efficiency of 7.04%at-0.75 V(vs.reversible hydrogen electrode)in 0.01 M Dulbecco’s Phosphate Buffered Saline.Moreover,it displays decent electrochemical stability over 30,000 s.Besides,the electrochemical NRR mechanism for MoO_(3)-CeO_(x)is investigated by in-situ Fourier transform infrared spectroscopy.N-H stretching,H-N-H bending,and N-N stretching are detected during the reaction,suggesting that an associative pathway is followed.This work provides an approach to designing and synthesizing potential electrocatalysts for NRR.展开更多
Spherical, monodispersed europium hydroxycarbonate particles wereobtained by homogeneous precipitation with urea in aqueous solution of Eu.(NO3)3at elevated temperature.The particles were readily converted to the unif...Spherical, monodispersed europium hydroxycarbonate particles wereobtained by homogeneous precipitation with urea in aqueous solution of Eu.(NO3)3at elevated temperature.The particles were readily converted to the uniformEu2O3 with average particle size of 50nm after calcined at 750℃.展开更多
A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was stu...A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was studied and discussed by phenomenological model. It is suggested that ultrafine monodispersed colloidal particles of Y(OH)CO3 are stable only in a very narrow temporary supersaturation range ( 1<x<1 .08).展开更多
Monodispersed potymeric microparticles were prepared by seed-poly- merization.High performance packings were obtained for anion chromatography by coating the surface-sutfonated partictes with quarternized latexes.
A cerium-triethanolamine complex was obtained by the reaction of cerium(III) nitrate and triethanolamine in ethanol solution. Spontaneous oxidation of cerium(III) to cerium(IV) by oxygen occurred during the reaction. ...A cerium-triethanolamine complex was obtained by the reaction of cerium(III) nitrate and triethanolamine in ethanol solution. Spontaneous oxidation of cerium(III) to cerium(IV) by oxygen occurred during the reaction. The complex was crystalline and soluble in water. Nanosized ceria (CeO2) particles could be prepared via hydrolysis of the complex in aqueous solution, and the extent of agglomeration of particles increased with the increase in temperature for hydrolysis. Under the low temperature of 25 oC, mon...展开更多
Monodispersed manganese ferrite （MnFe2O4） nanocrystals could be successfully synthesized in large quantities via a facile synthetic technique based on the pyrolysis of organometallic compound precursor, in which oct...Monodispersed manganese ferrite （MnFe2O4） nanocrystals could be successfully synthesized in large quantities via a facile synthetic technique based on the pyrolysis of organometallic compound precursor, in which octadecene was used as solvent, and oleic acid and oleylamine were used as capping ligands. MnFe204 nanocrystals were obtained with size in a tunable range of 4- 15 nm and their morphologies could be tuned from spherical to triangle-shaped by varying the surfactants. The phase structure, morphology, and size of the products were characterized in detail by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Magnetic properties of MnFe2O4 nanocrystals with different morphologies were measured using a superconducting quantum interference device （SQUID）. Both monodisperse MnFe204 nanocrystals with spherical and triangle-shapes are superparamagnetic at room temperature while ferromagnetic at 2 K. The pyrolysis method may provide an effective route to synthesize other spinel ferrites or metal oxides nanocrystals.展开更多
In this paper, zinc acetate, manganese acetate and thiacetamide are used as raw materials to successfully synthesize monodispersed ZnS：Mn^2＋ microspheres by using hydrothermal method and taking P123 surfactant as a ...In this paper, zinc acetate, manganese acetate and thiacetamide are used as raw materials to successfully synthesize monodispersed ZnS：Mn^2＋ microspheres by using hydrothermal method and taking P123 surfactant as a template. The products were characterized by XRD, STEM, FT-IR and N2 adsorption-desorption. And the results show that the diameter of this microsphere is 1.0 μm or so, which is larger than that of ZnS microsphere without Mn^2＋ doping, and it has monodispersion, smooth surface and uniform size, The doping of Mn^2＋ does not obviously change the structure of monodispersed ZnS microsphere. The photoluminescence peak lies in a wide band ranging from 450 to 650 nm, and the microspheres emit orange light; with the increase of Mn^2＋ concentration, fluorescence intensity of ZnS：Mn^2＋ microsphere changes, and when the mole ratio of Mn^2＋：Zn^2＋ is 0.3：1, the fluorescence intensity is the strongest.展开更多
The present, paper contains a new composite material Co;O;UFP sol prepared by using W/O microemulsion method, and its size distribution, interracial and optical nonlincar properties are discussed. The method for the p...The present, paper contains a new composite material Co;O;UFP sol prepared by using W/O microemulsion method, and its size distribution, interracial and optical nonlincar properties are discussed. The method for the preparation of UFP sol is as follows: at first, CoCl;and DBS so-展开更多
The controllable preparation and development of a practical photocatalytic material with yolk-shelled structure remains a great challenge.Herein,monodispersed yolk-shelled molybdenum disulfide microspheres have been s...The controllable preparation and development of a practical photocatalytic material with yolk-shelled structure remains a great challenge.Herein,monodispersed yolk-shelled molybdenum disulfide microspheres have been synthesized via a facile and economical hydrothermal method with the assistance of a surfactant(polyethylene-polypropylene glycol(P123)).Ostwald ripening is the main formation mechanism for the yolk-shelled structure.The photocatalytic activity of the sample is evaluated by monitoring the photodegradation of rhodamine B(RhB)under white light illumination(500 W xenon lamp)with the assistance of hydrogen peroxide(H_(2)O_(2)).The results indicate that the yolk-shelled microspheres display excellent photocatalytic activity and recycling stability.The photocatalytic degradation rate of yolk-shelled MoS_(2)microspheres is 97.6%after only 30 min,which is much higher than those of MoS_(2)particles synthesized without P123,MoS_(2)solid microspheres and commercial MoS_(2)(Experimental section)(54.7%,4.6%and 9.6%at 30 min,respectively).The reaction rate constant(k)of the yolk-shelled microspheres for the photodegradation of RhB is 1.19×10^(-1)min^(-1),which is 1.58,92.97 and 107.21 times faster than those of MoS_(2)particles(k_(2)=7.51×10^(-2)),MoS_(2)solid microspheres(k_(3)=1.28×10^(-3))and commercial MoS_(2)(k_(4)=1.11×10^(-3)),respectively.Such a highly desired yolk-shelled structure enables higher multiple light reflections and scattering between the outer spherical shell and the interior core compared with MoS_(2)particles,MoS_(2)solid microspheres and commercial MoS_(2)to provide a more efficient way of enhancing light-harvesting efficiency.展开更多
A nanocomposite anode material consisting fully of monodispersed copper phosphide(Cu3P)nanocrystals in situ grown in three-dimensional(3D)nitrogen-doped reduced graphene oxide(N-RGO)matrices has been manufactured via ...A nanocomposite anode material consisting fully of monodispersed copper phosphide(Cu3P)nanocrystals in situ grown in three-dimensional(3D)nitrogen-doped reduced graphene oxide(N-RGO)matrices has been manufactured via a“heating-up”synthesis,which involves nucleation,nitrogen-doping,crystallization and ligand exchange.The“heating-up”synthesis approach,using stable and relatively low-toxicity precursors and 3D porous N-RGO as the matrix,is straightforward,cost-effective and up-scalable.The Cu3P nanocrystals with an average size of 25–40 nm are wrapped,without aggregation,within the interior and on the surface of the curling N-RGO matrices.The resultant Cu_(3)P/N-RGO nanocomposites possess a 3D porous nanostructure with a BET surface area as high as 405.71 m^(2) g^(−1).In this nanostructure,the N-RGO’s properties of excellent conductivity and an interconnected porous network enable the Cu_(3)P/N-RGO nanocomposites to provide pathways for rapid electron transfer and lithium ion transport,and the Cu3P nanocrystals with their small size and monodispersed phase can accommodate the volume change during charging/discharging processes.Hence,Cu_(3)P/N-RGO nanocomposites reveal an excellent lithium-storage performance in terms of a long-life cycling stability(705.5 mA h g^(−1) at 10C,88.8%capacity retention over 1000 cycles at 25℃),a high heat-resistance capability(674.6 mA h g^(−1) under 10C,88.9%capacity retention over 1000 cycles at 55℃),and a high rate capability(604.6 mA h g^(−1) at 50C).展开更多
Atomically dispersed iron-nitrogen coordinated active sites on carbon(Fe-N-C)are considered to be absorbing materials that can be used as alternatives to Pt-based catalysts for the electrochemical oxygen reduction rea...Atomically dispersed iron-nitrogen coordinated active sites on carbon(Fe-N-C)are considered to be absorbing materials that can be used as alternatives to Pt-based catalysts for the electrochemical oxygen reduction reaction(ORR).However,Fe-N-C catalysts exhibit low metal loadings and unsatisfactory performance due to the imperfect electronic structure.Herein,atomically dispersed binary Fe-Fe dual-atom sites supported on hierarchically ordered porous N-doped carbon(denoted as FeNC-OAc)were synthesized via a universal carboxylate-assisted strategy.The iron ions could be stabilized by carboxylate,which promoted the formation of a Fe-Fe dual-atom catalyst with dense accessible active sites.Thanks to the high activity and accessibility of binary Fe-Fe active sites,the optimized 0.2FeNC-OAc catalyst exhibited superior oxygen reduction performance in alkaline solution,with a half-wave potential(E1/2)of 0.875 V,much higher than commercial 40 wt%Pt/C(0.853 V).Moreover,it displayed superior tolerance to methanol cross effects and electrochemical durability.This work affords a general method for the rapid preparation of electrocatalysts with bimetal active sites,which may promote the application of various atomic catalysts.展开更多
Methods allowing passive daytime radiative cooling(PDRC)to be carried out in an energy-efficient and scalable way are potentially important for various disciplines.Here,we report a sustainable strategy for scalable-de...Methods allowing passive daytime radiative cooling(PDRC)to be carried out in an energy-efficient and scalable way are potentially important for various disciplines.Here,we report a sustainable strategy for scalable-designed and color-regulating PDRC coating based on high-crystallinity photonic metamaterial(crystallinity:71.5%;enhanced assembly efficiency:72%),that is derived from the as-prepared 55 wt%solid content poly(methyl methacrylate-butyl acrylate-methacrylic acid)P(MMA-BA-MAA)monodispersed latexes(approaching theoretical limit:59 wt%).Robust meter-scale PDRC coatings are constructed by various industrial modes onto diverse surfaces,addressing bottlenecks like dull appearance,high cost,low efficiency,and hard construction.Notably,the solar reflectance,long-wave infrared emittance,and calculated theoretical cooling power of the designed PDRC coating,respectively,reach~0.94,~0.97,and~95.5 W m^(-2)under solar radiation,which can achieve an average 5.3℃ sub-ambient daytime temperature drop in the summer in Nanjing.The cooling performance,scale preparation,and cost-effectiveness of the PDRC coating have extended into leading position compared with those of state-of-the-art designs.This work provides promising route to reduce carbon emissions and energy consumption for global sustainability.展开更多
Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional ( 3-D ) ordered macroporous silica material after removing the tem...Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional ( 3-D ) ordered macroporous silica material after removing the template by calcination at high temperature. It was indicated that there existed highly ordered packed pores within the whole silica material by SEM morphology observation. It was also found that the pores were interconnected. The pore size could be controlled mainly by varying the particle size of the latex ranging from 101 to 102 nm. The formation process of the ordered pores was also preliminarily discussed.展开更多
In this paper, highly dispersive nanosized copper particles with a mean particle size of less than 6 nm are prepared by an environmentally friendly chemical reduction method. Non-toxic L-ascorbic acid acts as both red...In this paper, highly dispersive nanosized copper particles with a mean particle size of less than 6 nm are prepared by an environmentally friendly chemical reduction method. Non-toxic L-ascorbic acid acts as both reducing agent and antioxidant in ethylene glycol in the absence of any other capping agent. Transmission electron microscopy （TEM） is used to characterize the size and morphology of Cu nanoparticles. The results of UV-Vis spectroscopy （UV-Vis）, energy dispersive spectroscopy （EDS） and high resolution TEM （HRTEM） illustrate that the resultant product is pure Cu nanocrystals. The size of Cu nanoparticles is remarkably impacted by the order of reagent addition, and the investigation reveals the reaction procedure of Cu^2＋ ions and L-ascorbic acid.展开更多
The α-Fe_2 O_3@SiO_2 reddish pigments with core-shell structure were successfully prepared by hydrothermal and Stober methods. The structure, morphology, and chromaticity of the synthesized pigments were characterize...The α-Fe_2 O_3@SiO_2 reddish pigments with core-shell structure were successfully prepared by hydrothermal and Stober methods. The structure, morphology, and chromaticity of the synthesized pigments were characterized by XRD, SEM, TEM, FTIR, XPS, and colorimetry. The results indicated that the as-prepared pigments have the characteristics of narrow particle size distribution, high dispersion,and good sphericity. The α-Fe_2 O_3@SiO_2 reddish pigments were uniform and well dispersed in solution. In addition, the pigments with different shell thickness were also prepared, and the effect of shell thickness on the color performance of the pigments was discussed.展开更多
The preparations of superconducting thin films by DC, RF sputtering, laser evaporation and the MOCVD method have been reported. In order to extend the applications of high T<sub>c</sub> superconducting thi...The preparations of superconducting thin films by DC, RF sputtering, laser evaporation and the MOCVD method have been reported. In order to extend the applications of high T<sub>c</sub> superconducting thin films in industry, a homogeneous sol with monodispersed particles Y<sub>2</sub>O<sub>3</sub>, BaO and CuO in size of nanocrystalline 50—200 nm展开更多
Monodispersed particles of doped yttrium basic carbonates were prepared at aging at elevated temperature corresponding salts solutions in the presence of urea. Coprecipitation in mixed solutions of yttrium, lanthanum ...Monodispersed particles of doped yttrium basic carbonates were prepared at aging at elevated temperature corresponding salts solutions in the presence of urea. Coprecipitation in mixed solutions of yttrium, lanthanum and neodymium salts under similar experimental conditions yielded composite particles of basic carbonates. The content of the three metals in the solids followed closely the initial composition of the reacting solutions. On calcination all prepared solids converted to their corresponding oxides while retaining their particle morphology. The so-prepared powders were characterized by various techniques.展开更多
We report a facile method to synthesize dispersed Fe304@C nanoparticles （NPs）. Fe304 NPs were firstly prepared via the high temperature diol thermal decomposition method. Fe304@C NPs were fabricated using glucose as...We report a facile method to synthesize dispersed Fe304@C nanoparticles （NPs）. Fe304 NPs were firstly prepared via the high temperature diol thermal decomposition method. Fe304@C NPs were fabricated using glucose as a carbon source by hydro- thermal process. The obtained products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Raman spectra. The results indicate that the original shapes and magnetic property of Fe304 NPs can be well preserved. The magnetic particles are well dispersed in the carbon matrix. This strategy would provide an efficient approach for existing applications in Li-ion batteries and drug delivery. Meanwhile, it offers the raw materials to assemble future functional nanometer and micrometer superstructures.展开更多
Cobalt selenide(CoSe_(2))anchored monodisperse Pt presents good acidic 2e^(-)oxygen reduction reaction(ORR)performance;however,conventional preparation methods can only yield ultra-low content of Pt atom catalysts.It ...Cobalt selenide(CoSe_(2))anchored monodisperse Pt presents good acidic 2e^(-)oxygen reduction reaction(ORR)performance;however,conventional preparation methods can only yield ultra-low content of Pt atom catalysts.It is necessary to design catalysts with a high loading of monodisperse Pt to improve the activity and selectivity.Here,we reported anchoring highly reactive Pt atoms by constructing surface Co vacancies on CoSe_(2)(Pt_(1)/md-CoSe_(2)),thereby increasing the co ntent of Pt atoms.The monodisperse Pt is not only a reactive active site but also helps to improve the intrinsic activity of Co around Pt with a suitable electronic structu re,which contributes to the simultaneous enhancement of~*O_(2) adsorption and lowering of the reaction activation energy,accelerating the 2e^(-)ORR kinetics.The Pt_1/md-CoSe_(2) with a 0.2 wt%Pt exhibits high performa nce of electrocatalytic acidic 2e^(-)ORR.The H_(2)O_(2) yield is 1160.2 mmol g_(cat)^(-1).h^(-1)with a Faraday efficiency(FE)of 95.2%(0 V vs.RHE)at 0.1 M HClO_(4),superior to most of the reported literature.Moreover,the catalyst did not deactivate after a stability test of 30 h at the high current density of 100 mA cm^(-2).This work provides guidance for designing catalysts with applications and understanding the action mechanism of monodisperse Pt atoms.展开更多
文摘Monodispersed microsized copper oxalate particles were prepared in a segmented continuous flow tube reactor, and the effect of the main parameters such as organic additive agent, initial copper ions concentration, residence time, and segmented media on the final products were investigated experimentally. The obtained copper oxalate microsized particles were disc-like in the presence of citrate ligand,which was the shape inducer for the precipitated copper oxalate. Thermodynamic equilibrium diagrams of the Cu(Ⅱ)-oxalate-H_2O,Cu(Ⅱ)-oxalate-citrate-H_2O, and Cu(Ⅱ)-oxalate-EDTA-H_2O solution systems were drawn to estimate the possible copper species under the experimental conditions and to explain the formation mechanisms of copper oxalate particles in the segmented fluidic reactor. Both theoretical and experimental results indicated that the presence of chelating reagents such as citrate and EDTA had distinct effect on the evolution of particle shape. Air and kerosene were tested as media for the fluidic flow segmentation, and the latter was verified to better promote the growth of copper oxalate particles. The present study provides an easy method to prepare monodispersed copper oxalate microsized particles in a continuous scaling-up way, which can be utilized to prepare the precursor material for conductive inks.
基金financially supported by the National Key Research and Development Program of China(2017YFA0206500)NSFC(Grant Nos.21673198,91934303,21621091)。
文摘Developing efficient and low-cost electrocatalysts is essential for the electroreduction of N_(2) to NH_(3).Here,highly monodispersed MoO_(3) clusters loaded on a coral-like CeO_(x)compound with abundant oxygen vacancies are successfully prepared by an impregnation-reduction method.The MoO_(3) clusters with small sizes of 2.6±0.5 nm are induced and anchored by the oxygen vacancies of CeO_(x),resulting in excellent nitrogen reduction reaction(NRR)performance.Additionally,the synergistic effects between MoO_(3) and CeO_(x)lead to a further improvement of the electrochemical performance.The as-prepared MoO_(3)-CeO_(x)catalyst shows an NH_(3) yield rate of 32.2 μg h^(-1) mg^(-1) cat and a faradaic efficiency of 7.04%at-0.75 V(vs.reversible hydrogen electrode)in 0.01 M Dulbecco’s Phosphate Buffered Saline.Moreover,it displays decent electrochemical stability over 30,000 s.Besides,the electrochemical NRR mechanism for MoO_(3)-CeO_(x)is investigated by in-situ Fourier transform infrared spectroscopy.N-H stretching,H-N-H bending,and N-N stretching are detected during the reaction,suggesting that an associative pathway is followed.This work provides an approach to designing and synthesizing potential electrocatalysts for NRR.
文摘Spherical, monodispersed europium hydroxycarbonate particles wereobtained by homogeneous precipitation with urea in aqueous solution of Eu.(NO3)3at elevated temperature.The particles were readily converted to the uniformEu2O3 with average particle size of 50nm after calcined at 750℃.
文摘A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was studied and discussed by phenomenological model. It is suggested that ultrafine monodispersed colloidal particles of Y(OH)CO3 are stable only in a very narrow temporary supersaturation range ( 1<x<1 .08).
文摘Monodispersed potymeric microparticles were prepared by seed-poly- merization.High performance packings were obtained for anion chromatography by coating the surface-sutfonated partictes with quarternized latexes.
基金Project supported by the Provincal Major Science and Technology Special Projects of Zhejiang Province (2006 C11172)
文摘A cerium-triethanolamine complex was obtained by the reaction of cerium(III) nitrate and triethanolamine in ethanol solution. Spontaneous oxidation of cerium(III) to cerium(IV) by oxygen occurred during the reaction. The complex was crystalline and soluble in water. Nanosized ceria (CeO2) particles could be prepared via hydrolysis of the complex in aqueous solution, and the extent of agglomeration of particles increased with the increase in temperature for hydrolysis. Under the low temperature of 25 oC, mon...
基金Project(2010QZZD008) supported by the Prospect Key Projects of Fundamental Research Funds for the Central UniversitiesProject(2007FJ3008) supported by the Hunan Provincial Key Science and Technology Program of China
文摘Monodispersed manganese ferrite （MnFe2O4） nanocrystals could be successfully synthesized in large quantities via a facile synthetic technique based on the pyrolysis of organometallic compound precursor, in which octadecene was used as solvent, and oleic acid and oleylamine were used as capping ligands. MnFe204 nanocrystals were obtained with size in a tunable range of 4- 15 nm and their morphologies could be tuned from spherical to triangle-shaped by varying the surfactants. The phase structure, morphology, and size of the products were characterized in detail by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Magnetic properties of MnFe2O4 nanocrystals with different morphologies were measured using a superconducting quantum interference device （SQUID）. Both monodisperse MnFe204 nanocrystals with spherical and triangle-shapes are superparamagnetic at room temperature while ferromagnetic at 2 K. The pyrolysis method may provide an effective route to synthesize other spinel ferrites or metal oxides nanocrystals.
基金the Fujian Hi-tech Project Foundation (No. 2004H008)
文摘In this paper, zinc acetate, manganese acetate and thiacetamide are used as raw materials to successfully synthesize monodispersed ZnS：Mn^2＋ microspheres by using hydrothermal method and taking P123 surfactant as a template. The products were characterized by XRD, STEM, FT-IR and N2 adsorption-desorption. And the results show that the diameter of this microsphere is 1.0 μm or so, which is larger than that of ZnS microsphere without Mn^2＋ doping, and it has monodispersion, smooth surface and uniform size, The doping of Mn^2＋ does not obviously change the structure of monodispersed ZnS microsphere. The photoluminescence peak lies in a wide band ranging from 450 to 650 nm, and the microspheres emit orange light; with the increase of Mn^2＋ concentration, fluorescence intensity of ZnS：Mn^2＋ microsphere changes, and when the mole ratio of Mn^2＋：Zn^2＋ is 0.3：1, the fluorescence intensity is the strongest.
基金Supported by the National Natural Science Foundation of China
文摘The present, paper contains a new composite material Co;O;UFP sol prepared by using W/O microemulsion method, and its size distribution, interracial and optical nonlincar properties are discussed. The method for the preparation of UFP sol is as follows: at first, CoCl;and DBS so-
基金Natural Science Foundation of Anhui Province(1708085ME96)National Natural Science Foundation of China(51571166 and 61505167)+2 种基金Key Natural Science Research Project for Colleges and Universities of Anhui Province(KJ2016A638 and KJ2018B06)Basic Research Fund for Free Exploration(JCYJ20170815161437298 and 20170806223012689)foundation of the Anhui Provincial Education Department for Outstanding Young Talents in University(gxyq2017155)。
文摘The controllable preparation and development of a practical photocatalytic material with yolk-shelled structure remains a great challenge.Herein,monodispersed yolk-shelled molybdenum disulfide microspheres have been synthesized via a facile and economical hydrothermal method with the assistance of a surfactant(polyethylene-polypropylene glycol(P123)).Ostwald ripening is the main formation mechanism for the yolk-shelled structure.The photocatalytic activity of the sample is evaluated by monitoring the photodegradation of rhodamine B(RhB)under white light illumination(500 W xenon lamp)with the assistance of hydrogen peroxide(H_(2)O_(2)).The results indicate that the yolk-shelled microspheres display excellent photocatalytic activity and recycling stability.The photocatalytic degradation rate of yolk-shelled MoS_(2)microspheres is 97.6%after only 30 min,which is much higher than those of MoS_(2)particles synthesized without P123,MoS_(2)solid microspheres and commercial MoS_(2)(Experimental section)(54.7%,4.6%and 9.6%at 30 min,respectively).The reaction rate constant(k)of the yolk-shelled microspheres for the photodegradation of RhB is 1.19×10^(-1)min^(-1),which is 1.58,92.97 and 107.21 times faster than those of MoS_(2)particles(k_(2)=7.51×10^(-2)),MoS_(2)solid microspheres(k_(3)=1.28×10^(-3))and commercial MoS_(2)(k_(4)=1.11×10^(-3)),respectively.Such a highly desired yolk-shelled structure enables higher multiple light reflections and scattering between the outer spherical shell and the interior core compared with MoS_(2)particles,MoS_(2)solid microspheres and commercial MoS_(2)to provide a more efficient way of enhancing light-harvesting efficiency.
基金financial support from Natural Science Foundation of Heilongjiang Province(no.B2018009)the Colleges and Universities’Basic Scientific Research Business Expenses Projects of Heilongjiang Province(no.RCCX201714)+1 种基金the Youth Science and Technology Innovation Team Project of Heilongjiang Province(no.2018-KYYWF-1593)National Natural Science Foundation of China(no.21773060).
文摘A nanocomposite anode material consisting fully of monodispersed copper phosphide(Cu3P)nanocrystals in situ grown in three-dimensional(3D)nitrogen-doped reduced graphene oxide(N-RGO)matrices has been manufactured via a“heating-up”synthesis,which involves nucleation,nitrogen-doping,crystallization and ligand exchange.The“heating-up”synthesis approach,using stable and relatively low-toxicity precursors and 3D porous N-RGO as the matrix,is straightforward,cost-effective and up-scalable.The Cu3P nanocrystals with an average size of 25–40 nm are wrapped,without aggregation,within the interior and on the surface of the curling N-RGO matrices.The resultant Cu_(3)P/N-RGO nanocomposites possess a 3D porous nanostructure with a BET surface area as high as 405.71 m^(2) g^(−1).In this nanostructure,the N-RGO’s properties of excellent conductivity and an interconnected porous network enable the Cu_(3)P/N-RGO nanocomposites to provide pathways for rapid electron transfer and lithium ion transport,and the Cu3P nanocrystals with their small size and monodispersed phase can accommodate the volume change during charging/discharging processes.Hence,Cu_(3)P/N-RGO nanocomposites reveal an excellent lithium-storage performance in terms of a long-life cycling stability(705.5 mA h g^(−1) at 10C,88.8%capacity retention over 1000 cycles at 25℃),a high heat-resistance capability(674.6 mA h g^(−1) under 10C,88.9%capacity retention over 1000 cycles at 55℃),and a high rate capability(604.6 mA h g^(−1) at 50C).
基金supported by the Natural Science Foundation of Guangxi Province(ZY21195038 and 2020GXNSFGA297004)the National Natural Science Foundation of China(22179026,52161035,and U20A20237)+2 种基金the Science and Technology Development Project of Guilin(20210102-4)the Guilin Lijiang Scholar Foundation,the Guangxi Bagui Scholar Foundation,the Key Foundation of Educational Commission of Anhui Province(2022AH050376 and KJ2021A0518)the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202208).
文摘Atomically dispersed iron-nitrogen coordinated active sites on carbon(Fe-N-C)are considered to be absorbing materials that can be used as alternatives to Pt-based catalysts for the electrochemical oxygen reduction reaction(ORR).However,Fe-N-C catalysts exhibit low metal loadings and unsatisfactory performance due to the imperfect electronic structure.Herein,atomically dispersed binary Fe-Fe dual-atom sites supported on hierarchically ordered porous N-doped carbon(denoted as FeNC-OAc)were synthesized via a universal carboxylate-assisted strategy.The iron ions could be stabilized by carboxylate,which promoted the formation of a Fe-Fe dual-atom catalyst with dense accessible active sites.Thanks to the high activity and accessibility of binary Fe-Fe active sites,the optimized 0.2FeNC-OAc catalyst exhibited superior oxygen reduction performance in alkaline solution,with a half-wave potential(E1/2)of 0.875 V,much higher than commercial 40 wt%Pt/C(0.853 V).Moreover,it displayed superior tolerance to methanol cross effects and electrochemical durability.This work affords a general method for the rapid preparation of electrocatalysts with bimetal active sites,which may promote the application of various atomic catalysts.
基金support of the National Natural Science Foundation of China(grant 22508184 to X.Q.Y.,grant 21736006 to S.C.,and grant 22278225 to S.C.)supported by the Natural Funding Program of Jiangsu Province(grant BK20250610 to X.Q.Y.).
文摘Methods allowing passive daytime radiative cooling(PDRC)to be carried out in an energy-efficient and scalable way are potentially important for various disciplines.Here,we report a sustainable strategy for scalable-designed and color-regulating PDRC coating based on high-crystallinity photonic metamaterial(crystallinity:71.5%;enhanced assembly efficiency:72%),that is derived from the as-prepared 55 wt%solid content poly(methyl methacrylate-butyl acrylate-methacrylic acid)P(MMA-BA-MAA)monodispersed latexes(approaching theoretical limit:59 wt%).Robust meter-scale PDRC coatings are constructed by various industrial modes onto diverse surfaces,addressing bottlenecks like dull appearance,high cost,low efficiency,and hard construction.Notably,the solar reflectance,long-wave infrared emittance,and calculated theoretical cooling power of the designed PDRC coating,respectively,reach~0.94,~0.97,and~95.5 W m^(-2)under solar radiation,which can achieve an average 5.3℃ sub-ambient daytime temperature drop in the summer in Nanjing.The cooling performance,scale preparation,and cost-effectiveness of the PDRC coating have extended into leading position compared with those of state-of-the-art designs.This work provides promising route to reduce carbon emissions and energy consumption for global sustainability.
文摘Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional ( 3-D ) ordered macroporous silica material after removing the template by calcination at high temperature. It was indicated that there existed highly ordered packed pores within the whole silica material by SEM morphology observation. It was also found that the pores were interconnected. The pore size could be controlled mainly by varying the particle size of the latex ranging from 101 to 102 nm. The formation process of the ordered pores was also preliminarily discussed.
基金Acknowledgement This work is sponsored by the National Natural Science Foundation of China （No. 51202175） and the Natural Science Foundation of Hubei Province （No. 2011 CDB245）.
文摘In this paper, highly dispersive nanosized copper particles with a mean particle size of less than 6 nm are prepared by an environmentally friendly chemical reduction method. Non-toxic L-ascorbic acid acts as both reducing agent and antioxidant in ethylene glycol in the absence of any other capping agent. Transmission electron microscopy （TEM） is used to characterize the size and morphology of Cu nanoparticles. The results of UV-Vis spectroscopy （UV-Vis）, energy dispersive spectroscopy （EDS） and high resolution TEM （HRTEM） illustrate that the resultant product is pure Cu nanocrystals. The size of Cu nanoparticles is remarkably impacted by the order of reagent addition, and the investigation reveals the reaction procedure of Cu^2＋ ions and L-ascorbic acid.
基金financially supported by the Initiative Scientific Research Program from Jingdezheng Ceramic Institute and SRT Program (No. 1721T0264) from Tsinghua University
文摘The α-Fe_2 O_3@SiO_2 reddish pigments with core-shell structure were successfully prepared by hydrothermal and Stober methods. The structure, morphology, and chromaticity of the synthesized pigments were characterized by XRD, SEM, TEM, FTIR, XPS, and colorimetry. The results indicated that the as-prepared pigments have the characteristics of narrow particle size distribution, high dispersion,and good sphericity. The α-Fe_2 O_3@SiO_2 reddish pigments were uniform and well dispersed in solution. In addition, the pigments with different shell thickness were also prepared, and the effect of shell thickness on the color performance of the pigments was discussed.
基金Project supported by the National Natural Science Foundation of China.
文摘The preparations of superconducting thin films by DC, RF sputtering, laser evaporation and the MOCVD method have been reported. In order to extend the applications of high T<sub>c</sub> superconducting thin films in industry, a homogeneous sol with monodispersed particles Y<sub>2</sub>O<sub>3</sub>, BaO and CuO in size of nanocrystalline 50—200 nm
文摘Monodispersed particles of doped yttrium basic carbonates were prepared at aging at elevated temperature corresponding salts solutions in the presence of urea. Coprecipitation in mixed solutions of yttrium, lanthanum and neodymium salts under similar experimental conditions yielded composite particles of basic carbonates. The content of the three metals in the solids followed closely the initial composition of the reacting solutions. On calcination all prepared solids converted to their corresponding oxides while retaining their particle morphology. The so-prepared powders were characterized by various techniques.
基金supported by the National Natural Science Foundation of China(11274033,61227902,11474015)the Research Fund for the Doctoral Program of Higher Education of China(20131102130005)+2 种基金the Fundamental Research Funds for the Central Universities(YWF-14-RSC-119,YWF-15-WLXY-012)China Scholarship Council(201506025052)Beijing Key Discipline Foundation of Condensed Matter Physics
文摘We report a facile method to synthesize dispersed Fe304@C nanoparticles （NPs）. Fe304 NPs were firstly prepared via the high temperature diol thermal decomposition method. Fe304@C NPs were fabricated using glucose as a carbon source by hydro- thermal process. The obtained products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Raman spectra. The results indicate that the original shapes and magnetic property of Fe304 NPs can be well preserved. The magnetic particles are well dispersed in the carbon matrix. This strategy would provide an efficient approach for existing applications in Li-ion batteries and drug delivery. Meanwhile, it offers the raw materials to assemble future functional nanometer and micrometer superstructures.
基金financial support from the National Natural Science Foundation of China(22408196)financial support from the National Natural Science Foundation of China(22379082)+2 种基金the Natural Science Foundation of Shandong(ZR2022QB236)the supported by the State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology(Grant No.MJNYSKL202402)the Taishan Scholars Program(tsqn201909119)。
文摘Cobalt selenide(CoSe_(2))anchored monodisperse Pt presents good acidic 2e^(-)oxygen reduction reaction(ORR)performance;however,conventional preparation methods can only yield ultra-low content of Pt atom catalysts.It is necessary to design catalysts with a high loading of monodisperse Pt to improve the activity and selectivity.Here,we reported anchoring highly reactive Pt atoms by constructing surface Co vacancies on CoSe_(2)(Pt_(1)/md-CoSe_(2)),thereby increasing the co ntent of Pt atoms.The monodisperse Pt is not only a reactive active site but also helps to improve the intrinsic activity of Co around Pt with a suitable electronic structu re,which contributes to the simultaneous enhancement of~*O_(2) adsorption and lowering of the reaction activation energy,accelerating the 2e^(-)ORR kinetics.The Pt_1/md-CoSe_(2) with a 0.2 wt%Pt exhibits high performa nce of electrocatalytic acidic 2e^(-)ORR.The H_(2)O_(2) yield is 1160.2 mmol g_(cat)^(-1).h^(-1)with a Faraday efficiency(FE)of 95.2%(0 V vs.RHE)at 0.1 M HClO_(4),superior to most of the reported literature.Moreover,the catalyst did not deactivate after a stability test of 30 h at the high current density of 100 mA cm^(-2).This work provides guidance for designing catalysts with applications and understanding the action mechanism of monodisperse Pt atoms.
