The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure const...The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials.In the present work,layer-structured Co-metal-organic frameworks(Co-MOFs)precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method.After annealed at 500℃ under Ar atmosphere,a novel multiscale hierarchical composite(Co@C/CF)was obtained with the support of carbon fibers,keeping the flower-like structure.Scanning electron microscope,transmission electron microscope,X-ray diffraction,Raman,and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure,and the microwave absorption performance of the Co@C/CF composites were investigated.The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio.The optimized Co@C/CF flower-like composites achieved the best reflection loss of−55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm,with the corresponding effective absorption bandwidth(EAB)of 2.1 GHz.The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm.The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure.The flower-like structure not only balanced the impedance of the fibers themselves,but also extended the propagation path of the microwave and then increased the multiple reflection losses.This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.展开更多
The self-assembly of two-dimensional(2D)semiconductor nanosheets into three-dimensional(3D)ordered superstructures represents an ingenious way to avoid aggregation,expose massive available active sites and benefit the...The self-assembly of two-dimensional(2D)semiconductor nanosheets into three-dimensional(3D)ordered superstructures represents an ingenious way to avoid aggregation,expose massive available active sites and benefit the mass transfer,which maximizes the advantages of the 2D nanostructures in photo-catalysis.Herein,a flower-like superstructure of ternary semiconducting boron carbon nitride nanosheets(FS-BCNNSs)was synthesized through the morphology-preserved thermal transformation of a flower-like superstructure of boron-containing metal-organic framework nanosheets(FS-MOFNSs).Taking advantage of this functional superstructure,FS-BCNNSs was employed for the pioneering application in the field of photocatalytic hydrogen peroxide(H_(2)O_(2))production and exhibited excellent photocatalytic performance,yielding an impressive rate of 1415.9μmol g^(−1)h^(−1)for the production of H_(2)O_(2).The results of this work offer not just a promising catalyst for photocatalytic H_(2)O_(2)production but also a facile strategy to fabricate unique superstructures constructed from 2D nanosheets for catalysis,energy conversion,and other related fields.展开更多
Flower-like NaY（MoO4）2 particles were synthesized through a microwave-assisted hydrother- mal process followed by a subsequent calcination process. The products were characterized by X-ray diffraction, X-ray photoel...Flower-like NaY（MoO4）2 particles were synthesized through a microwave-assisted hydrother- mal process followed by a subsequent calcination process. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron mi- croscopy. The possible formation mechanism of the flower-like NaY（MoO4）2 precursor was proposed. The NaY（MoO4）2：Eu3＋ phosphors were also prepared and their luminescence properties showed the NaY（MoO4）2：Eu^3＋ materials with the emission peak at 612 nm had potential application as a red phosphor for white light-emitting diodes. Furthermore, the microwave-assisted hydrothermal process followed by a subsequent calcination process could be extended to prepare the other lanthanide molybdates with the flower-like morphology.展开更多
A flower-like Eu^2＋ and Dy^3＋ co-doped SrAl2O4 long-lasting phosphorescent （LLP） phosphor was synthesized via the inorganic- salt-based sol-gel method. The crystal structure, morphology and optical properties of t...A flower-like Eu^2＋ and Dy^3＋ co-doped SrAl2O4 long-lasting phosphorescent （LLP） phosphor was synthesized via the inorganic- salt-based sol-gel method. The crystal structure, morphology and optical properties of the composite were characterized. X-ray diffraction diffusion （XRD） data and DSC-TG curves of the phosphor revealed that the SrAl2O4 crystallites have been formed after the precursor was calcined at 900 ℃ and to be single-phase SrA1204 at 1100 ℃. The SEM photographs indicated that the sample exhibited a universal flower-like morphology with crystallite size of about l-2μm. After being irradiated with ultraviolet （UV） light, the flower-like phosphor emitted long-lasting green phosphorescence with an excitation peak at 365 nm and emission peak at 500 nm which was ascribed to the characteristic 5d-4f transition of Eu^2＋. Both the PL spectra and the luminance decay curve revealed that this phosphor exhibited efficient luminescence and long lasting properties.展开更多
Magnesium hydride has been seen as a potential material for solid state hydrogen storage,but the kinetics and thermodynamics obstacles have hindered its development and application.Three-dimensional flower-like TiO2@C...Magnesium hydride has been seen as a potential material for solid state hydrogen storage,but the kinetics and thermodynamics obstacles have hindered its development and application.Three-dimensional flower-like TiO2@C and TiO2 were synthesized as the catalyst for MgH2 system and great catalytic activities are acquired in the hydrogen sorption properties.Experiments also show that the flower-like TiO2@C is superior to flower-like TiO2 in improving the hydrogen storage properties of MgH2.The hydrogen desorption onset and peak temperatures of flower-like TiO2 doped MgH2 is reduced to 199.2℃and 245.4℃,while the primitive MgH2 starts to release hydrogen at 294.6℃and the rapid dehydrogenation temperature is even as high as 362.6℃.The onset and peak temperatures of flower-like TiO2@C doped MgH2 are further reduced to 180.3℃and 233.0℃.The flower-like TiO2@C doped MgH2 composite can release6.0 wt%hydrogen at 250℃within 7 min,and 4.86 wt%hydrogen at 225℃within 60 min,while flowerlike TiO2 doped MgH2 can release 6.0 wt%hydrogen at 250℃within 8 min,and 3.89 wt%hydrogen at225℃within 60 min.Hydrogen absorption kinetics is also improved dramatically.Moreover,compared with primitive MgH2 and the flower-like TiO2 doped MgH2,the activation energy of flower-like TiO2@C doped MgH2 is significantly decreased to 67.10 kJ/mol.All the improvement of hydrogen sorption properties can be ascribed to the flower-like structure and the two-phase coexistence of TiO2 and amorphous carbon.Such phase composition and unique structure are proved to be the critical factor to improve the hydrogen sorption properties of MgH2,which can be considered as the new prospect for improving the kinetics of light-metal hydrogen storage materials.展开更多
Electrochemical conversion of CO2 into fuel has been regarded as a promising approach to achieve the global carbon cycle.Herein,we report an efficient cobalt catalyst with a unique flower-like morphology synthesized b...Electrochemical conversion of CO2 into fuel has been regarded as a promising approach to achieve the global carbon cycle.Herein,we report an efficient cobalt catalyst with a unique flower-like morphology synthesized by a green and facile hydrothermal method,in which n-butylamine is used as the capping agent.The resultant catalyst shows superior electrocatalytic activity toward CO2 electroreduction,which is highly selective for generating formate with a Faraday efficiency of 63.4%.Electrochemical analysis reveals that the oxide on the surface is essential for the electrocatalysis of the CO2 reduction reaction.Cyclic voltammograms further suggest that this catalyst is highly active for the oxidation of reduced product,and can thus be seen as a bifunctional catalyst.展开更多
This work elucidates the synthesis and characterization of copper ions incorporated ceria(Ce1-xCuxO2)nanocatalysts with 3 D flower-like and nanocrystalline morphology for the purification of automobile exhausts. XRD a...This work elucidates the synthesis and characterization of copper ions incorporated ceria(Ce1-xCuxO2)nanocatalysts with 3 D flower-like and nanocrystalline morphology for the purification of automobile exhausts. XRD and Raman results confirm the presence of copper ions in ceria. The 3 D flower-like and nanocrystalline morphology exhibited by these catalysts were seen by FESEM images. HRTEM and SAED results confirm that(100) plane is dominantly presented in 3 D flower-like Ce1-xCuxO2catalysts when compared to nanocrystalline morphology. The textural properties of synthesized catalysts was done with the help of N2 sorption study, which confirms that flower-like Ce1-xCuxO2catalysts show high surface area and pore volume. The existence of Ce3+, Ce4+, Cu+and Cu2+ions in the catalyst were examined by XPS and DR UV-Vis techniques. Oxygen storage capacity(OSC) of the catalysts was studied by H2-TPR analysis. These characterization results elucidate the presence of dominant active sites(Ce3+, Ce4+, Cu+and Cu2+) and {100} plane in the flower-like morphology compared to nanocrystalline. The catalytic activity of synthesized Ce1-xCuxO2catalysts was tested for removal of CO, HCxand NO gases from automobile emission with respect to the copper content and morphology. The obtained results indicate that the presence of optimum amount of copper in ceria with flower-like morphology is essential for the removal of CO, HCxand NO at low temperature via redox process, which is due to the presence of active sites on the dominant {100} plane.展开更多
A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,st...A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,structural features,energy band structures and photoelectrochemical properties were systematically studied.All the Ag/BMO/rGO ternary composites(AgBGy;y=1%,2%and 3%)demonstrated greater photocatalytic activity towards efficient removal of our selected organic models[methyl orange(MO),rhodamine B(RhB)and phenol],as compared with the BMO/rGO binary composites(BG-x;x=0.25,2,4 and 5).Particularly,AgBG-2%,which was synthesized with the addition of 2 wt% rGO and 2 wt%Ag in BMO,possessed superior photocatalytic activity.The fitted rate constants(k)for the photocatalytic degradation of RhB,MO and phenol using AgBG-2% were estimated to be 0.0286,0.0301 and 0.0165 min^(-1),respectively,which were over one order of magnitude greater than those obtained using pure BMO.Several factors may contribute to the observed enhancement,including greater specific surface area,enhanced light absorption,promoted spatial separation of electronhole(e^(-)-h^(+))pairs and their suppressed recombination,especially benefiting from the synergistic effects among BMO,rGO and Ag NPs.Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water.展开更多
In this work,we put forward a scheme to exquisitely design and selectively synthesize the core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites(MCNCs)through a simple two-st...In this work,we put forward a scheme to exquisitely design and selectively synthesize the core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites(MCNCs)through a simple two-step hydrothermal reaction on the surfaces of MFe_(2)O_4 nanospheres with the certain amounts of Mo and Se sources.With increasing the amounts of Mo and Se sources,the obtained core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)MCNCs with the enhanced content of MoSe_(2)and improved flower-like geometry morphology could be produced on a large scale.The obtained results revealed that the as-prepared samples displayed improved comprehensive microwave absorption properties(CMAPs)with the increased amounts of Mo and Se sources.The as-prepared CoSe_(2)/FeSe_(2)@MoSe_(2)and NiSe_(2)/FeSe_(2)@MoSe_(2)MCNCs with the well-defined flower-like morphology could simultaneously present the outstanding CMAPs in terms of strong absorption capability,wide absorption bandwidth,and thin matching thicknesses,which mainly originated from the conduction loss and flower-like geometry morphology.Therefore,the findings not only develop the very desirable candidates for high-performance microwave absorption materials but also pave a new way for optimizing the CMAPs through tailoring morphology engineering.展开更多
Superior electromagnetic(EM)wave absorption properties in 8.2-12.4 GHz(X-band)can be obtained via the effective combination of polyaniline(PANI)and CuS.Herein,novel 3D flower-like hollow CuS@PANI microspheres were fab...Superior electromagnetic(EM)wave absorption properties in 8.2-12.4 GHz(X-band)can be obtained via the effective combination of polyaniline(PANI)and CuS.Herein,novel 3D flower-like hollow CuS@PANI microspheres were fabricated by a solvothermal process followed by in-situ polymerization.EM wave absorption properties of 3D flower-like hollow CuS@PANI microspheres in X-band were systematically studied,indicating the minimum reflection loss(RL_(min))of-71.1 dB and effective absorption bandwidth(EAB)covering 81%of test frequency range were achieved with a thickness of 2.75 mm.Excellent EM wave absorption properties of 3D flower-like hollow CuS@PANI microspheres were mainly ascribed to outstanding impedance matching characteristic and dielectric loss capability(conduction loss,interfacial polarization loss and dipole polarization loss).Moreover,due to the distinctive flower-like hollow struc-ture of CuS@PANI microspheres,an additional wave-absorbing mechanism was provided by increasing the transmission paths of EM waves.展开更多
Employing zinc sulfate solution obtained from zinc oxide ore as raw material,sodium hydroxide as precipitant and PEG20000 as dispersant,ultrafine ZnO powders with different morphologies were successfully synthesized t...Employing zinc sulfate solution obtained from zinc oxide ore as raw material,sodium hydroxide as precipitant and PEG20000 as dispersant,ultrafine ZnO powders with different morphologies were successfully synthesized through hydrothermal method.The influences of the dosage of PEG20000 solution,molar ratio of OH-/Zn2+,reaction temperature,reaction time and Zn2+concentration on the structures and morphologies of the ZnO powders were discussed in detail.The reaction conditions of synthesizing ZnO powders with flower-like structure were obtained as below:dosage of PEG20000 with 10%mass fraction 5 mL,molar ratio of OH-to Zn2+5,reaction temperature 150℃,reaction time 8 h at Zn2+concentration1 mol L-1.The growth mechanism of ZnO particles with different morphologies was proposed.The ZnO powder with flower-like structure are composed of multiple micro-rods with hexagon morphology and has good photocatalytic degradation ability to degrade Rh B.20 mL Rh B solution with 15 mgL-1 could be completely degraded over flower-like ZnO powder 300 mg within 3 h.展开更多
TiO2@Ni(OH)2 core-shell microspheres were synthesized by a facile strategy to obtain a perfect 3D flower-like nanostructure with well-arranged Ni(OH)2 nanoflakes on the surfaces of TiO2 microspheres;this arrangement l...TiO2@Ni(OH)2 core-shell microspheres were synthesized by a facile strategy to obtain a perfect 3D flower-like nanostructure with well-arranged Ni(OH)2 nanoflakes on the surfaces of TiO2 microspheres;this arrangement led to a six-fold enhancement in photocatalytic hydrogen evolution. The unique p-n type heterostructure not only promotes the separation and transfer of photogenerated charge carriers significantly, but also offers more active sites for photocatalytic hydrogen production. A photocatalytic mechanism is proposed based on the results of electrochemical measurements and X-ray photoelectron spectroscopy.展开更多
Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO_(4)/(NH_(4))_(2)SO_(4) as a raw material.The effect of the operating parameters of the hydrothermal temperature, OH...Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO_(4)/(NH_(4))_(2)SO_(4) as a raw material.The effect of the operating parameters of the hydrothermal temperature, OH^(-)/Zn^(2+) molar ratio, time, and amount of dispersant on the phase structure and micromorphology of the ZnO particles were investigated.The synthesis conditions of the flower-like ZnO microstructures were: hydrothermal temperature of 160℃, OH^(-)/Zn^(2+) molar ratio of 5:1, reaction time of 4 h, and 4 mL of dispersant.The flower-like ZnO microstructures were comprised of hexagon-shaped ZnO rods arranged in a radiatively.Degradation experiments of Rhodamine B with the flower-like ZnO microstructures demonstrated a degradation efficiency of 97.6% after 4 h of exposure to sunshine, indicating excellent photocatalytic capacity.The growth mechanism of the flower-like ZnO microstructures was presented.展开更多
In this study, flower-like mesoporous TiO_2 hierarchical spheres(FMTHSs) with ordered stratified structure and TiO_2 nanoparticles(TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multil...In this study, flower-like mesoporous TiO_2 hierarchical spheres(FMTHSs) with ordered stratified structure and TiO_2 nanoparticles(TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multilamellar vesicles(MTSVs) and unilamellar TiO_2/SiO_2 vesicles(UTSVs) were prepared using cetyltrimethylammonium bromide and didodecyldimethylammonium bromide as structure-directing agents under different solvothermal conditions. FMTHSs and TNPs were obtained from the etching reactions of MTSVs and UTSVs, respectively, in an alkaline system. FMTHSs display flower-like, ordered stratified structures on each petal. The thickness of the ordered stratified structure is approximately3–6 nm, and the number of layers is approximately 2–4. The FMTHSs2 electrode exhibits the first discharge capacity of 212.4 m A h g^(-1) at 0.2 C, which is higher than that of TNPs electrode(167.6 mA h g^(-1)).The discharge specific capacity of FMTHSs2 electrode after 200 cycles at 1 C is 105.9 mA h g^(-1), which is higher than that of TNPs electrode(52.2 mA h g^(-1)) after the same number of cycles. The outstanding performance of FMTHSs2 electrode is attributed to the advantages of FMTHSs. In particular, their own stratified structure can provide additional active sites for reactions. The hierarchical structure can provide short diffusion length for Li^+, large electrolyte–electrode contact area, and superior accommodation of the strain of Li+intercalation/deintercalation.展开更多
Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprint...Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprinted materials and expand the application fields of graphene materials,novel surface molecular imprinted polymers(MIPs)based on magnetic graphene microspheres Fe_(3)O_(4)@r GO@MIPs are first synthesized in this paper.Fe_(3)O_(4)@r GO@MIPs are prepared by oxidative self-polymerization of dopamine on the surface of magnetic graphene(Fe_(3)O_(4)@r GO)composite microspheres.Bovine serum albumin(BSA)is selected as protein template.Fe_(3)O_(4)@r GO microspheres with wrinkled flower-like structure are obtained by compounding Fe_(3)O_(4)and graphene oxide in an appropriate ratio via the method of high-temperature reduction self-assembly.The microspheres exhibit promising dispersibility,high external surface area,rich pore structure,and sufficient magnetic properties.These advantages not only prevent the agglomeration of imprinted microspheres in the aqueous phase,which is conducive to contact and static adsorption,but also increase the amount of protein imprinting.Additionally,sufficient magnetic properties ensure fast and effective separation of the adsorbents.While the adsorption capacity is increased,the separation procedure becomes simple.The binding capacity of Fe_(3)O_(4)@r GO@MIPs for BSA can reach 317.58 mg/g within 60 min,and the imprinting factor(IF)is 4.24.More importantly,Fe_(3)O_(4)@r GO@MIPs can specifically recognize the target BSA from the mixed proteins and the actual sample.There is no significant decrease in the adsorption amount,IF,and magnetic properties after eight runs.It is promising to be used in the separation of proteins from the actual biological samples.展开更多
A novel flower-like hydrated magnesium carbonate hydroxide, Mg5 （CO3 ）4 （OH）2·4H2O, with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use o...A novel flower-like hydrated magnesium carbonate hydroxide, Mg5 （CO3 ）4 （OH）2·4H2O, with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use of template or organic surfactant. Reaction time has an important effect on the final morphology of the product. The micro-structure and morphology of Mg5 （CO3）4 （OH）2·4H2O were characterized by means of X-ray diffractometry （XRD）, fieldemission scanning electron microscopy（FE-SEM）. Brunauer-Emmett-Teller（BET） surface areas of the samples were also measured. The probable formation mechanism of flower-like micro-structure was discussed. It was found that Mg5 （CO3）4（ OH）2·4H2O with flower-like micro-structure was a novel and efficient catalyst for the synthesis of diphenyl carbonate （DPC） by transesterification of dimethyl carbonate （DMC） with phenol.展开更多
Finding easy-to-operate strategy to obtain anode material with well-designed structure and excellent electrochemical performance is necessary to promote the development of the future potassium-ion batteries(PIBs).In t...Finding easy-to-operate strategy to obtain anode material with well-designed structure and excellent electrochemical performance is necessary to promote the development of the future potassium-ion batteries(PIBs).In this work,we synthesized reduced graphene oxide doping flower-like Fe_(7)S_(8) nanosheets electrode materials using one-step hydrothermal strategy.The rGO@Fe_(7)S_(8) composite is composed of homogeneous Fe_(7)S_(8) and reduced graphene oxide thin nanosheets.This unique structure not only promotes the penetration of electrolyte and increases the conductive of the pure Fe_(7)S_(8) electrode materials,but also relieves the volume expansion of K^(+) during charge/discharge process.When applied this interesting anode electrode for PIBs,the rGO@Fe_(7)S_(8) exhibits excellent electrochemical performance.It delivers a high reversible specific capacity of 445 mAh g^(-1) at 50 mA g^(-1),excellent rate performance(284 mAhg^(-1)at 500 mA g^(-1) and 237 mAh g^(-1) at 1000 mA g^(-1)),and a high cycling stability at 100 mA g^(-1)(maintained 355 mAh g^(-1) after 300 cycles).展开更多
The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave absorber.However,how to fully exploit its wave-absorbing potential re-mains a thoug...The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave absorber.However,how to fully exploit its wave-absorbing potential re-mains a thought-provoking question.Here,we have synthesized Fe/Fe_(4)N@SiO_(2)nanomagnetic core-shell materials with different Fe/Fe_(4)N ratios by performing nitridation reactions at different temperatures.Then,the flower-like core-shell Fe/Fe_(4)N@SiO_(2)structure was obtained by the etching method.Finally,with the synergy of the excellent magnetic and dielectric losses,an outstanding absorption performance could be achieved with a minimum refection loss(RL min)of−71.31 dB at the matching thickness of 1.4 mm,and the widest effective absorption bandwidth(EAB max)of 6.1 GHz less than−10 dB was realized at 1.16 mm.Moreover,this material also shows a preeminent advance in corrosion resistance to adapt to harsh environments.Hence,this iron nitride flower-like core-shell structure exhibits great potential in microwave absorption in harsh conditions.展开更多
Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio ...Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio of 1:0.5,temperature of 120°C and time of 1 h at Mg^(2+)concentration of 2 mol/L.Spherical flower-like Mg(OH)_(2) composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Fe^(3+)and Co^(2+),and the adsorption reaches the equilibrium in 6 min.The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)_(2) at 20°C are 58.55,85.84,44.94,485.44,625.00 and 27.86 mg/g,respectively.The adsorption is well fitted by the Langmuir model,indicating that the adsorption is monolayer.The adsorption kinetics follows the pseudo-second-order model.Chemisorption is the operative mechanism.Spherical flower-like Mg(OH)_(2) is a qualified candidate for heavy metal ions removal.展开更多
Pd/CeO2 catalysts with flower-like morphology were fabricated via an ultrasonic-assisted membrane reduction （UAMR） and hydrothermal methods. The catalysts were physically characterized and evaluated for three-way ca...Pd/CeO2 catalysts with flower-like morphology were fabricated via an ultrasonic-assisted membrane reduction （UAMR） and hydrothermal methods. The catalysts were physically characterized and evaluated for three-way catalytic activities versus tradi- tional Pd/CeO2 catalysts. Flower-like Pd/CeO2 catalysts exhibited a higher catalytic performance and better thermal stability than the Pd/CeO2 prepared by conventional impregnation. The flower-like Pd/CeO2 catalysts were constructed from 20-50 nm thick nanosheet petals. These petals were in turn constructed from 10 nm CeO2 nanoparticles that self-assembled into the flower-like morphology re- sulting in abundant pores in all directions. The Pd nanoparticles were anchored and dispersed on both the interior and surface of the pores and had minimal sintering. When these catalysts were aged, the structure and morphology of the catalysts remained unchanged with important industrial implications for this new type of material including improved catalytic performance and high thermal stabil- ity. Regardless of the Pd loading, both the fresh and aged Pd/CeO2 catalysts prepared by the UAMR-hydrothermal method exhibited better performance than the corresponding samples prepared by conventional impregnation means.展开更多
基金financially supported by the National Natural Science of Foundation of China(No.52371097)the Shenyang Unveiling and Leading Project,China(No.22-301-1-01)。
文摘The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials.In the present work,layer-structured Co-metal-organic frameworks(Co-MOFs)precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method.After annealed at 500℃ under Ar atmosphere,a novel multiscale hierarchical composite(Co@C/CF)was obtained with the support of carbon fibers,keeping the flower-like structure.Scanning electron microscope,transmission electron microscope,X-ray diffraction,Raman,and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure,and the microwave absorption performance of the Co@C/CF composites were investigated.The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio.The optimized Co@C/CF flower-like composites achieved the best reflection loss of−55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm,with the corresponding effective absorption bandwidth(EAB)of 2.1 GHz.The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm.The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure.The flower-like structure not only balanced the impedance of the fibers themselves,but also extended the propagation path of the microwave and then increased the multiple reflection losses.This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.
基金supported by the National Natural Science Foundation of China(No.51702365)the Natural Science Foundation of Shandong Province(No.ZR2022MB133)+1 种基金Key Research and Development Plan of Shandong Province(Nos.2019GGX102056,2018GGX104018)New Faculty Start-up funding in China University of Petroleum(East China)(No.YJ201501029).
文摘The self-assembly of two-dimensional(2D)semiconductor nanosheets into three-dimensional(3D)ordered superstructures represents an ingenious way to avoid aggregation,expose massive available active sites and benefit the mass transfer,which maximizes the advantages of the 2D nanostructures in photo-catalysis.Herein,a flower-like superstructure of ternary semiconducting boron carbon nitride nanosheets(FS-BCNNSs)was synthesized through the morphology-preserved thermal transformation of a flower-like superstructure of boron-containing metal-organic framework nanosheets(FS-MOFNSs).Taking advantage of this functional superstructure,FS-BCNNSs was employed for the pioneering application in the field of photocatalytic hydrogen peroxide(H_(2)O_(2))production and exhibited excellent photocatalytic performance,yielding an impressive rate of 1415.9μmol g^(−1)h^(−1)for the production of H_(2)O_(2).The results of this work offer not just a promising catalyst for photocatalytic H_(2)O_(2)production but also a facile strategy to fabricate unique superstructures constructed from 2D nanosheets for catalysis,energy conversion,and other related fields.
文摘Flower-like NaY（MoO4）2 particles were synthesized through a microwave-assisted hydrother- mal process followed by a subsequent calcination process. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron mi- croscopy. The possible formation mechanism of the flower-like NaY（MoO4）2 precursor was proposed. The NaY（MoO4）2：Eu3＋ phosphors were also prepared and their luminescence properties showed the NaY（MoO4）2：Eu^3＋ materials with the emission peak at 612 nm had potential application as a red phosphor for white light-emitting diodes. Furthermore, the microwave-assisted hydrothermal process followed by a subsequent calcination process could be extended to prepare the other lanthanide molybdates with the flower-like morphology.
基金Project supported by the National Natural Science Foundation of China (20671042,50872045)Natural Science Foundation of Guangdong Province (05200555,7005918)
文摘A flower-like Eu^2＋ and Dy^3＋ co-doped SrAl2O4 long-lasting phosphorescent （LLP） phosphor was synthesized via the inorganic- salt-based sol-gel method. The crystal structure, morphology and optical properties of the composite were characterized. X-ray diffraction diffusion （XRD） data and DSC-TG curves of the phosphor revealed that the SrAl2O4 crystallites have been formed after the precursor was calcined at 900 ℃ and to be single-phase SrA1204 at 1100 ℃. The SEM photographs indicated that the sample exhibited a universal flower-like morphology with crystallite size of about l-2μm. After being irradiated with ultraviolet （UV） light, the flower-like phosphor emitted long-lasting green phosphorescence with an excitation peak at 365 nm and emission peak at 500 nm which was ascribed to the characteristic 5d-4f transition of Eu^2＋. Both the PL spectra and the luminance decay curve revealed that this phosphor exhibited efficient luminescence and long lasting properties.
基金financial supports for this research from the National Basic Research Program of China(2018YFB1502104)the National Natural Science Foundation of China(51571179 and 51671173)the Open Fund of the Guangdong Provincial Key Laboratory of Advance Energy Storage Materials。
文摘Magnesium hydride has been seen as a potential material for solid state hydrogen storage,but the kinetics and thermodynamics obstacles have hindered its development and application.Three-dimensional flower-like TiO2@C and TiO2 were synthesized as the catalyst for MgH2 system and great catalytic activities are acquired in the hydrogen sorption properties.Experiments also show that the flower-like TiO2@C is superior to flower-like TiO2 in improving the hydrogen storage properties of MgH2.The hydrogen desorption onset and peak temperatures of flower-like TiO2 doped MgH2 is reduced to 199.2℃and 245.4℃,while the primitive MgH2 starts to release hydrogen at 294.6℃and the rapid dehydrogenation temperature is even as high as 362.6℃.The onset and peak temperatures of flower-like TiO2@C doped MgH2 are further reduced to 180.3℃and 233.0℃.The flower-like TiO2@C doped MgH2 composite can release6.0 wt%hydrogen at 250℃within 7 min,and 4.86 wt%hydrogen at 225℃within 60 min,while flowerlike TiO2 doped MgH2 can release 6.0 wt%hydrogen at 250℃within 8 min,and 3.89 wt%hydrogen at225℃within 60 min.Hydrogen absorption kinetics is also improved dramatically.Moreover,compared with primitive MgH2 and the flower-like TiO2 doped MgH2,the activation energy of flower-like TiO2@C doped MgH2 is significantly decreased to 67.10 kJ/mol.All the improvement of hydrogen sorption properties can be ascribed to the flower-like structure and the two-phase coexistence of TiO2 and amorphous carbon.Such phase composition and unique structure are proved to be the critical factor to improve the hydrogen sorption properties of MgH2,which can be considered as the new prospect for improving the kinetics of light-metal hydrogen storage materials.
文摘Electrochemical conversion of CO2 into fuel has been regarded as a promising approach to achieve the global carbon cycle.Herein,we report an efficient cobalt catalyst with a unique flower-like morphology synthesized by a green and facile hydrothermal method,in which n-butylamine is used as the capping agent.The resultant catalyst shows superior electrocatalytic activity toward CO2 electroreduction,which is highly selective for generating formate with a Faraday efficiency of 63.4%.Electrochemical analysis reveals that the oxide on the surface is essential for the electrocatalysis of the CO2 reduction reaction.Cyclic voltammograms further suggest that this catalyst is highly active for the oxidation of reduced product,and can thus be seen as a bifunctional catalyst.
基金the UGC meritorious fellowship for providing financial support
文摘This work elucidates the synthesis and characterization of copper ions incorporated ceria(Ce1-xCuxO2)nanocatalysts with 3 D flower-like and nanocrystalline morphology for the purification of automobile exhausts. XRD and Raman results confirm the presence of copper ions in ceria. The 3 D flower-like and nanocrystalline morphology exhibited by these catalysts were seen by FESEM images. HRTEM and SAED results confirm that(100) plane is dominantly presented in 3 D flower-like Ce1-xCuxO2catalysts when compared to nanocrystalline morphology. The textural properties of synthesized catalysts was done with the help of N2 sorption study, which confirms that flower-like Ce1-xCuxO2catalysts show high surface area and pore volume. The existence of Ce3+, Ce4+, Cu+and Cu2+ions in the catalyst were examined by XPS and DR UV-Vis techniques. Oxygen storage capacity(OSC) of the catalysts was studied by H2-TPR analysis. These characterization results elucidate the presence of dominant active sites(Ce3+, Ce4+, Cu+and Cu2+) and {100} plane in the flower-like morphology compared to nanocrystalline. The catalytic activity of synthesized Ce1-xCuxO2catalysts was tested for removal of CO, HCxand NO gases from automobile emission with respect to the copper content and morphology. The obtained results indicate that the presence of optimum amount of copper in ceria with flower-like morphology is essential for the removal of CO, HCxand NO at low temperature via redox process, which is due to the presence of active sites on the dominant {100} plane.
基金financially supported by National Natural Science Foundation of China(Nos.21607064 and 21707055)the Youth Key Project of Nature Science Foundation of Jiangxi Province(Nos.20192ACBL20014 and 20192ACBL21011)+2 种基金the Natural Science Foundation of Jiangxi Province(Nos.20181BAB203018 and 20181BAB213010)Qingjiang Youth Talent Program(No.JXUSTQJYX20170005)the scholarship under China S cholarship Council(No.201803000004)。
文摘A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,structural features,energy band structures and photoelectrochemical properties were systematically studied.All the Ag/BMO/rGO ternary composites(AgBGy;y=1%,2%and 3%)demonstrated greater photocatalytic activity towards efficient removal of our selected organic models[methyl orange(MO),rhodamine B(RhB)and phenol],as compared with the BMO/rGO binary composites(BG-x;x=0.25,2,4 and 5).Particularly,AgBG-2%,which was synthesized with the addition of 2 wt% rGO and 2 wt%Ag in BMO,possessed superior photocatalytic activity.The fitted rate constants(k)for the photocatalytic degradation of RhB,MO and phenol using AgBG-2% were estimated to be 0.0286,0.0301 and 0.0165 min^(-1),respectively,which were over one order of magnitude greater than those obtained using pure BMO.Several factors may contribute to the observed enhancement,including greater specific surface area,enhanced light absorption,promoted spatial separation of electronhole(e^(-)-h^(+))pairs and their suppressed recombination,especially benefiting from the synergistic effects among BMO,rGO and Ag NPs.Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water.
基金financially supported by the Fund of Fok Ying Tung Education Foundationthe Major Research Project of innovative Group of Guizhou province(2018–013)+2 种基金the Open Fund from Henan University of Science and Technologythe National Science Foundation of China(Nos.11964006 and 11774156)the Foundation of the National Key Project for Basic Research(No.2012CB932304)。
文摘In this work,we put forward a scheme to exquisitely design and selectively synthesize the core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites(MCNCs)through a simple two-step hydrothermal reaction on the surfaces of MFe_(2)O_4 nanospheres with the certain amounts of Mo and Se sources.With increasing the amounts of Mo and Se sources,the obtained core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)MCNCs with the enhanced content of MoSe_(2)and improved flower-like geometry morphology could be produced on a large scale.The obtained results revealed that the as-prepared samples displayed improved comprehensive microwave absorption properties(CMAPs)with the increased amounts of Mo and Se sources.The as-prepared CoSe_(2)/FeSe_(2)@MoSe_(2)and NiSe_(2)/FeSe_(2)@MoSe_(2)MCNCs with the well-defined flower-like morphology could simultaneously present the outstanding CMAPs in terms of strong absorption capability,wide absorption bandwidth,and thin matching thicknesses,which mainly originated from the conduction loss and flower-like geometry morphology.Therefore,the findings not only develop the very desirable candidates for high-performance microwave absorption materials but also pave a new way for optimizing the CMAPs through tailoring morphology engineering.
基金supported by PhD Research Startup Foundation of Bohai University(No.0521bs021).
文摘Superior electromagnetic(EM)wave absorption properties in 8.2-12.4 GHz(X-band)can be obtained via the effective combination of polyaniline(PANI)and CuS.Herein,novel 3D flower-like hollow CuS@PANI microspheres were fabricated by a solvothermal process followed by in-situ polymerization.EM wave absorption properties of 3D flower-like hollow CuS@PANI microspheres in X-band were systematically studied,indicating the minimum reflection loss(RL_(min))of-71.1 dB and effective absorption bandwidth(EAB)covering 81%of test frequency range were achieved with a thickness of 2.75 mm.Excellent EM wave absorption properties of 3D flower-like hollow CuS@PANI microspheres were mainly ascribed to outstanding impedance matching characteristic and dielectric loss capability(conduction loss,interfacial polarization loss and dipole polarization loss).Moreover,due to the distinctive flower-like hollow struc-ture of CuS@PANI microspheres,an additional wave-absorbing mechanism was provided by increasing the transmission paths of EM waves.
基金supported financially by the National Natural Science Foundation of China(Nos.51774070 and 51574084)the National Key R&D Program of China(No.2017YFB0305401)。
文摘Employing zinc sulfate solution obtained from zinc oxide ore as raw material,sodium hydroxide as precipitant and PEG20000 as dispersant,ultrafine ZnO powders with different morphologies were successfully synthesized through hydrothermal method.The influences of the dosage of PEG20000 solution,molar ratio of OH-/Zn2+,reaction temperature,reaction time and Zn2+concentration on the structures and morphologies of the ZnO powders were discussed in detail.The reaction conditions of synthesizing ZnO powders with flower-like structure were obtained as below:dosage of PEG20000 with 10%mass fraction 5 mL,molar ratio of OH-to Zn2+5,reaction temperature 150℃,reaction time 8 h at Zn2+concentration1 mol L-1.The growth mechanism of ZnO particles with different morphologies was proposed.The ZnO powder with flower-like structure are composed of multiple micro-rods with hexagon morphology and has good photocatalytic degradation ability to degrade Rh B.20 mL Rh B solution with 15 mgL-1 could be completely degraded over flower-like ZnO powder 300 mg within 3 h.
基金supported by the National Natural Science Foundation of China(21773031)the Natural Science Foundation of Fujian Province(2018J01686)the State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE-2017A01 and SKLPEE-2017B02)~~
文摘TiO2@Ni(OH)2 core-shell microspheres were synthesized by a facile strategy to obtain a perfect 3D flower-like nanostructure with well-arranged Ni(OH)2 nanoflakes on the surfaces of TiO2 microspheres;this arrangement led to a six-fold enhancement in photocatalytic hydrogen evolution. The unique p-n type heterostructure not only promotes the separation and transfer of photogenerated charge carriers significantly, but also offers more active sites for photocatalytic hydrogen production. A photocatalytic mechanism is proposed based on the results of electrochemical measurements and X-ray photoelectron spectroscopy.
基金financially supported by the Funding of Shenyang Ligong University’s Research Support Program for High-level Talents (No.1010147000802)the National Natural Science Foundation of China (Nos.52004165 and 51774070)。
文摘Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO_(4)/(NH_(4))_(2)SO_(4) as a raw material.The effect of the operating parameters of the hydrothermal temperature, OH^(-)/Zn^(2+) molar ratio, time, and amount of dispersant on the phase structure and micromorphology of the ZnO particles were investigated.The synthesis conditions of the flower-like ZnO microstructures were: hydrothermal temperature of 160℃, OH^(-)/Zn^(2+) molar ratio of 5:1, reaction time of 4 h, and 4 mL of dispersant.The flower-like ZnO microstructures were comprised of hexagon-shaped ZnO rods arranged in a radiatively.Degradation experiments of Rhodamine B with the flower-like ZnO microstructures demonstrated a degradation efficiency of 97.6% after 4 h of exposure to sunshine, indicating excellent photocatalytic capacity.The growth mechanism of the flower-like ZnO microstructures was presented.
基金supported by the National Natural Science Foundation of China (Grant Nos.51372134 and 51572124)
文摘In this study, flower-like mesoporous TiO_2 hierarchical spheres(FMTHSs) with ordered stratified structure and TiO_2 nanoparticles(TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multilamellar vesicles(MTSVs) and unilamellar TiO_2/SiO_2 vesicles(UTSVs) were prepared using cetyltrimethylammonium bromide and didodecyldimethylammonium bromide as structure-directing agents under different solvothermal conditions. FMTHSs and TNPs were obtained from the etching reactions of MTSVs and UTSVs, respectively, in an alkaline system. FMTHSs display flower-like, ordered stratified structures on each petal. The thickness of the ordered stratified structure is approximately3–6 nm, and the number of layers is approximately 2–4. The FMTHSs2 electrode exhibits the first discharge capacity of 212.4 m A h g^(-1) at 0.2 C, which is higher than that of TNPs electrode(167.6 mA h g^(-1)).The discharge specific capacity of FMTHSs2 electrode after 200 cycles at 1 C is 105.9 mA h g^(-1), which is higher than that of TNPs electrode(52.2 mA h g^(-1)) after the same number of cycles. The outstanding performance of FMTHSs2 electrode is attributed to the advantages of FMTHSs. In particular, their own stratified structure can provide additional active sites for reactions. The hierarchical structure can provide short diffusion length for Li^+, large electrolyte–electrode contact area, and superior accommodation of the strain of Li+intercalation/deintercalation.
基金the National Natural Science Foundation of China(No.21704084,21975206)the Shaanxi Innovative Talents Promotion Plan-the Young Star of Science and Technology Project(No.2019KJXX-67)。
文摘Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprinted materials and expand the application fields of graphene materials,novel surface molecular imprinted polymers(MIPs)based on magnetic graphene microspheres Fe_(3)O_(4)@r GO@MIPs are first synthesized in this paper.Fe_(3)O_(4)@r GO@MIPs are prepared by oxidative self-polymerization of dopamine on the surface of magnetic graphene(Fe_(3)O_(4)@r GO)composite microspheres.Bovine serum albumin(BSA)is selected as protein template.Fe_(3)O_(4)@r GO microspheres with wrinkled flower-like structure are obtained by compounding Fe_(3)O_(4)and graphene oxide in an appropriate ratio via the method of high-temperature reduction self-assembly.The microspheres exhibit promising dispersibility,high external surface area,rich pore structure,and sufficient magnetic properties.These advantages not only prevent the agglomeration of imprinted microspheres in the aqueous phase,which is conducive to contact and static adsorption,but also increase the amount of protein imprinting.Additionally,sufficient magnetic properties ensure fast and effective separation of the adsorbents.While the adsorption capacity is increased,the separation procedure becomes simple.The binding capacity of Fe_(3)O_(4)@r GO@MIPs for BSA can reach 317.58 mg/g within 60 min,and the imprinting factor(IF)is 4.24.More importantly,Fe_(3)O_(4)@r GO@MIPs can specifically recognize the target BSA from the mixed proteins and the actual sample.There is no significant decrease in the adsorption amount,IF,and magnetic properties after eight runs.It is promising to be used in the separation of proteins from the actual biological samples.
基金Supported by the National Natural Science Foundation of China(Nos.20671011,20331010,90406002and90406024)the 111 Project(No.B07012)the Key Laboratory of Structural Chemistry Foundation(No.060017).
文摘A novel flower-like hydrated magnesium carbonate hydroxide, Mg5 （CO3 ）4 （OH）2·4H2O, with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use of template or organic surfactant. Reaction time has an important effect on the final morphology of the product. The micro-structure and morphology of Mg5 （CO3）4 （OH）2·4H2O were characterized by means of X-ray diffractometry （XRD）, fieldemission scanning electron microscopy（FE-SEM）. Brunauer-Emmett-Teller（BET） surface areas of the samples were also measured. The probable formation mechanism of flower-like micro-structure was discussed. It was found that Mg5 （CO3）4（ OH）2·4H2O with flower-like micro-structure was a novel and efficient catalyst for the synthesis of diphenyl carbonate （DPC） by transesterification of dimethyl carbonate （DMC） with phenol.
基金financially supported by the National Natural Science Foundation of China(No.21872045)。
文摘Finding easy-to-operate strategy to obtain anode material with well-designed structure and excellent electrochemical performance is necessary to promote the development of the future potassium-ion batteries(PIBs).In this work,we synthesized reduced graphene oxide doping flower-like Fe_(7)S_(8) nanosheets electrode materials using one-step hydrothermal strategy.The rGO@Fe_(7)S_(8) composite is composed of homogeneous Fe_(7)S_(8) and reduced graphene oxide thin nanosheets.This unique structure not only promotes the penetration of electrolyte and increases the conductive of the pure Fe_(7)S_(8) electrode materials,but also relieves the volume expansion of K^(+) during charge/discharge process.When applied this interesting anode electrode for PIBs,the rGO@Fe_(7)S_(8) exhibits excellent electrochemical performance.It delivers a high reversible specific capacity of 445 mAh g^(-1) at 50 mA g^(-1),excellent rate performance(284 mAhg^(-1)at 500 mA g^(-1) and 237 mAh g^(-1) at 1000 mA g^(-1)),and a high cycling stability at 100 mA g^(-1)(maintained 355 mAh g^(-1) after 300 cycles).
基金supported by the National Natural Science Foun-dation of China(Nos.52071294 and U1809215)Natural Science Foundation of Zhejiang Province(Grant LY20E020015)National Key Research and Development Program(No.2019YFE012862).
文摘The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave absorber.However,how to fully exploit its wave-absorbing potential re-mains a thought-provoking question.Here,we have synthesized Fe/Fe_(4)N@SiO_(2)nanomagnetic core-shell materials with different Fe/Fe_(4)N ratios by performing nitridation reactions at different temperatures.Then,the flower-like core-shell Fe/Fe_(4)N@SiO_(2)structure was obtained by the etching method.Finally,with the synergy of the excellent magnetic and dielectric losses,an outstanding absorption performance could be achieved with a minimum refection loss(RL min)of−71.31 dB at the matching thickness of 1.4 mm,and the widest effective absorption bandwidth(EAB max)of 6.1 GHz less than−10 dB was realized at 1.16 mm.Moreover,this material also shows a preeminent advance in corrosion resistance to adapt to harsh environments.Hence,this iron nitride flower-like core-shell structure exhibits great potential in microwave absorption in harsh conditions.
基金supported by the National Natural Science Foundation of China (Nos. 51774070 and 52004165)the Science and Technology Project of Yunnan Province, China (No. 202101AS070029)
文摘Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio of 1:0.5,temperature of 120°C and time of 1 h at Mg^(2+)concentration of 2 mol/L.Spherical flower-like Mg(OH)_(2) composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Fe^(3+)and Co^(2+),and the adsorption reaches the equilibrium in 6 min.The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)_(2) at 20°C are 58.55,85.84,44.94,485.44,625.00 and 27.86 mg/g,respectively.The adsorption is well fitted by the Langmuir model,indicating that the adsorption is monolayer.The adsorption kinetics follows the pseudo-second-order model.Chemisorption is the operative mechanism.Spherical flower-like Mg(OH)_(2) is a qualified candidate for heavy metal ions removal.
基金Project supported by National Natural Science Foundation of China (20877006, 20833011)Beijing Municipal Natural Science Foundation (2101002)+2 种基金the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality (PHR201107104, PHR200907105)National High Technology Research and Development Program (2011AA03A406)National Industrial Project of New Rare Earth Materials
文摘Pd/CeO2 catalysts with flower-like morphology were fabricated via an ultrasonic-assisted membrane reduction （UAMR） and hydrothermal methods. The catalysts were physically characterized and evaluated for three-way catalytic activities versus tradi- tional Pd/CeO2 catalysts. Flower-like Pd/CeO2 catalysts exhibited a higher catalytic performance and better thermal stability than the Pd/CeO2 prepared by conventional impregnation. The flower-like Pd/CeO2 catalysts were constructed from 20-50 nm thick nanosheet petals. These petals were in turn constructed from 10 nm CeO2 nanoparticles that self-assembled into the flower-like morphology re- sulting in abundant pores in all directions. The Pd nanoparticles were anchored and dispersed on both the interior and surface of the pores and had minimal sintering. When these catalysts were aged, the structure and morphology of the catalysts remained unchanged with important industrial implications for this new type of material including improved catalytic performance and high thermal stabil- ity. Regardless of the Pd loading, both the fresh and aged Pd/CeO2 catalysts prepared by the UAMR-hydrothermal method exhibited better performance than the corresponding samples prepared by conventional impregnation means.
