In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) o...In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) or N-methyl- 2-pyrrolidone(NMP) on solvothermal synthesis of [Zn4O(BDC)3]8 were investigated through a combined DFT and experimental study. XRD and SEM showed that the absorbability of NMP in the pore of [Zn4O(BDC)3]8 was weaker than that of DMF. The thermal decomposition temperature of [Zn4O(BDC)3]8 synthesized in DMF was higher than that in NMP according to TG and FT-IR. In addition, the nitrogen sorption isotherms indicated that NMP improved gas sorption property of [Zn4O(BDC)3]8. The COSMO optimized calculations indicated that the total energy of Zn4O(BDC)3 in NMP was higher than that in DMF, and compared with non-solvent system, the charge of zinc atoms decreased and the charge value was the smallest in NMP. Furthermore, the interaction of DMF, NMP or DEF in [Zn4O(BDC)3]8 crystal model was calculated by DFT method. The results suggested that NMP should be easier to be removed from pore of materials than DMF from the point of view of energy state. It can be concluded that NMP was a favorable solvent to synthesize [Zn4O(BDC)3]8 and the microscopic mechanism was that the binding force between Zn4O(BDC)3 and NMP molecule was weaker than DMF.展开更多
Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resu...Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resulting in its much lower sodium storage performance than hard carbon. We propose a novel preoxidation strategy to introduce additional oxygen atoms into the low-cost soft carbon precursor pitch to fabricate a defect-rich and large-interlayer spacing hard carbon anode(HPP-1100). Compared with the direct pyrolysis of pitch carbon, the sodium storage capacity of HPP-1100 is significantly improved from 120.3 m Ah/g to 306.7 m Ah/g, with an excellent rate and cycling capability(116.5 m Ah/g at 10 C). Moreover, when assorted with an O_(3)-Na(NiFeMn)1/3O_(2)cathode, the full cell delivers a high reversible capacity of 274.0 m Ah/g at 0.1 C with superb cycle life. This work provides a new solution for realizing the application of low-cost pitch anodes in Na-ion batteries.展开更多
Aggregates of cerium dioxide nanoparticles(nano-CeO_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO_2 were syst...Aggregates of cerium dioxide nanoparticles(nano-CeO_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO_2 were systematically studied by X-ray diffraction(XRD),transmission electron microscopy(TEM), laser particle size analyzer(LA) and specific surface area and pore size analyzer during the solvothermal process. Among all the obtained samples, the 18-h solvothermal-prepared nano-CeO_2 aggregates show the best crystallinity and the largest specific surface area of 110.92 m^2·g^(-1). Owing to the high activity derived from the high specific surface area of the aggregates, the application as arsenic(As) adsorption was also studied. The adsorption efficiency of arsenic by nano-CeO_2 aggregates was established as the function of adsorbent dose, then pH value and at last adsorption time.The results indicate that the nano-CeO_2 aggregates show a high efficiency in removing arsenic from low As concentration solution, from which the nano-CeO_2 adsorbent could be easily separated. In addition, the adsorption kinetics is best fitted to pseudo-second-order model(R^2 = 0.99999).展开更多
Three-dimensional(3D) ultra-tiny Fe_(2)O_(3) nanoparticles/graphene hydrogels were prepared using a facile and efficient solvothermal reaction, by which the phase of iron oxide, particle size and the morphology of hyd...Three-dimensional(3D) ultra-tiny Fe_(2)O_(3) nanoparticles/graphene hydrogels were prepared using a facile and efficient solvothermal reaction, by which the phase of iron oxide, particle size and the morphology of hydrogels can be precisely controlled by simply adjusting the solvothermal reaction time. Accordingly, the effect of the microstructures of hydrogels on electrochemical performance was systematically studied. It was found that Fe_(2)O_(3)/r GO-50 hydrogels(with a solvothermal reaction time of 50 min) possessed a desirable crystallinity, suitable particle size, decent porous structure, large specific surface area and high electrical conductivity, thus exhibiting a superior electrochemical performance as binder-free anode of supercapacitors: a large potential range of 1.15 V, an ultrahigh specific capacitance of 1090 F·g^(-1) at a current density of 2A·g^(-1) and excellent rate capability (531 F·g^(-1) at 10 A·g^(-1)). The rational design and systematic research of electrode materials will provide new lights for the preparation of advanced electrochemical energy storage devices.展开更多
The well-distribution spindle Li Fe PO4(LFP)nanoparticles as cathode of lithium secondary batteries were synthesized by a solvothermal reaction route at low temperature(180 °C) in which the ascorbic acid was used...The well-distribution spindle Li Fe PO4(LFP)nanoparticles as cathode of lithium secondary batteries were synthesized by a solvothermal reaction route at low temperature(180 °C) in which the ascorbic acid was used as reducing agent. In order to guarantee that the p H values of thermal systems were not affected too much and the reducibility of the system was enhanced at the same time,glucose was chosen as an auxiliary reductant in this reaction. The obtained powders were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),and laser particle analyzer. The results show that the carbon-coated uniform spindle olivine Li Fe PO4/C-glucose particles(glucose as auxiliary reductant, LFP/C-G) are prepared with the size 500–600 nm and without any impurity phases. Their electrochemical properties were evaluated by electrochemical impedance spectroscopy,cyclic voltammetry, and galvanostatic charge/discharge tests. LFP/C-G has a higher conductivity and better reversible capability than carbon-coated LFP(LFP/C). The highest discharge capacity of LFP/C-G is 161.3 mAh·g-1at0.1C and 108.6 mAh·g-1at 5.0C, respectively. The results imply that the neat crystal nanostructure of LFP/C-G has excellent capacity retention and cycling stability.The adding of glucose is the key factor for the welldistribution and neat crystal structure of nanoparticles,thus the electrochemical performances of materials are improved.展开更多
Vanadium‐chromium oxides(VCrO)were usually prepared by high‐temperature solid‐state reactions;however,mixed phases were frequently produced and the morphology of the products was not well controlled.In this work,we...Vanadium‐chromium oxides(VCrO)were usually prepared by high‐temperature solid‐state reactions;however,mixed phases were frequently produced and the morphology of the products was not well controlled.In this work,we prepared amorphous VCrO precursors by using V2O5 and CrO3 and alcohols or mixtures of alcohol and water via solvothermal reaction at 180°C.The precursors were then calcined under nitrogen at various temperatures.The products were characterized by powder X‐ray diffraction,transmission electron microscopy,and X‐ray photoelectron spectroscopy.It was revealed that pure‐phase nanocrystalline orthorhombic CrVO4 was obtained when methanol or methanol/water was used as the solvothermal medium and the precursor was calcined at 700°C.The size of the CrVO4 crystals was around 500 nm when methanol was used,whereas it reduced significantly to less than 50 nm when a mixture of methanol and water was used.The sizes could be effectively tuned from 10 to 50 nm by varying the methanol/water volume ratio.To the best of our knowledge,this is the first report on the synthesis of pure‐phase CrVO4 nanocrystals.The nano‐CrVO4 showed almost the highest catalytic activity for the ammoxidation of 2,6‐dichlorotoluene to 2,6‐dichlorobenzonitrile among the reported bi‐component composite oxides,owing to its smaller particle size,larger specific surface area,and more exposed active centers.展开更多
As a potential substitute for LiFePO4, LiMnPO4 has attracted more and more attention due to its higher energy, showing potential application in electric vehicle(EV) or hybrid electric vehicle(HEV). In this work,so...As a potential substitute for LiFePO4, LiMnPO4 has attracted more and more attention due to its higher energy, showing potential application in electric vehicle(EV) or hybrid electric vehicle(HEV). In this work,solvothermal method was used to prepare nano-sized LiMnPO4, where ethylene glycol was used as solvent, and lithium acetate(LiAc), phosphoric acid(H3 PO4) and manganese chloride(MnCl2) were used as precursors. The crystal structure and morphology of the obtained products were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performance was evaluated by charge-discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the molar ratio of LiAc:H3 PO4:MnCl2 plays a critical role in directing the morphology of LiMnPO4. Large plates transform into irregular nanoparticles when the molar ratio changes from 2:1:1 to 6:1:1. After carbon coating, the product prepared from the 6:1:1 precursor could deliver discharge capacities of 156.9,122.8, and 89.7 mAhg-1 at 0.05 C, 1 C and 10 C, respectively.The capacity retention can be maintained at 85.1% after 200 cycles at 1 C rate for this product.展开更多
Hybrid composites of phosphomolybdic acid@UiO-66(PMo12@UiO-66)and Co-substituted phosphomolybdic acid@UiO-66(PMo11Co@UiO-66)were synthesized using the direct solvothermal method.A variety of characterization results d...Hybrid composites of phosphomolybdic acid@UiO-66(PMo12@UiO-66)and Co-substituted phosphomolybdic acid@UiO-66(PMo11Co@UiO-66)were synthesized using the direct solvothermal method.A variety of characterization results demonstrated that phosphomolybdic acid(PMo12)or Co-substituted phosphomolybdate acid(PMo11Co)clusters are uniformly dispersed in the cages of Zr-based metal-organic UiO-66 frameworks.The catalytic properties of these hybrid composites were investigated by applying the epoxidation of olefins with tert-butyl hydroperoxide as the oxidant.Compared to PMo12@UiO-66,PMo11Co@UiO-66 showed a much higher catalytic activity and was simply recovered by filtration and reused for at least ten runs without significant loss of catalytic activity.Particularly,PMo11Co@UiO-66 can efficiently convert cyclic olefins like limonenes to epoxides,and its selectivity to 1,2-limonene oxide reached 91%in the presence of a radical inhibitor such as hydroquinone.The excellent catalytic activity and stability of the hybrid composite PMo11Co@UiO-66 are mainly attributed to the uniform distribution of highly active PMo11Co units within the smaller cages of UiO-66,to the suitable surface polarity of the hybrid composite for facilitating the access of reagents and solvent,and to the strong interface-interactions between the polyoxometalate and the UiO-66 framework.展开更多
V2O3 nanoparticles with high surface area have been successfully prepared by a new solvothermal method without using any surfactant and template. The size of V2O3 nanoparticles is mostly equal to 10 nm-30 nm. The high...V2O3 nanoparticles with high surface area have been successfully prepared by a new solvothermal method without using any surfactant and template. The size of V2O3 nanoparticles is mostly equal to 10 nm-30 nm. The highest surface area of obtained V2O3 nanoparticles reaches 49 m2/g. Several kinds of V2O3 catalysts were prepared by different methods. All these V2O3 catalysts obtained thereby showed high catalytic activity for oxidative desulfurization(ODS) reaction by using tert-butyl hydroperoxide as the oxidant. The V2O3 catalyst with a highest ODS activity was obtained under the following conditions: The catalyst was prepared upon using V2O5 as the vanadium source, methanol as the solvent, and oxalic acid as the complexing reagent at a V2O5/oxalic acid molar ratio of 1:2. The process for ODS of dibenzothiophene was carried out under mild conditions(under atmospheric pressure and at a relatively low temperature). The highest ODS activity of the obtained V2O3 nanoparticles can be attributed to their highest surface area.展开更多
Y2O3 nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y2O3 in order to obtain better materials per...Y2O3 nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y2O3 in order to obtain better materials performance. In present study, yttrium oxyhydroxide precursor was synthesized via a facile solvothermal process through the dissolution-re-crystallization mechanism of Y2O3 raw powders in the ethylenediamine solvent, then nanosized yttrium oxide crystal was prepared from the precursor through post heat treatment process. The effects of solvothermal treatment temperature, holding time, solvent kinds and post heat treatment parameters on crystalline structure, grain shape and size of nanocrystal were investigated by XRD, TEM and TGA-DTA measurements. TEM images reveal that the morphology of product after post heat treatment at 460℃for 12 h is rice-like nanocrystal. XRD shows that this product is pure cubic Y2O3 cphase. Present study reveals that high purity Y2O3 with rice-like morphology can be easily prepared with average size around 30 nm under suitable post heat treatment parameters. In addition, the effects of solvents such as water and ethanol etc. on the crystal structure and morphology were also investigated. It is suggested that dissolution-recrystallization process may be the main mechanism for the formation of nano-sized YOOH precursors under solvothermal reaction condition, and the ethylenediamine solvent is likely to play an important role in controlling the transformation process of yttria precursors to the Y2O3 nanocrystal.展开更多
ZnIn2S4 microspheres have been solvothermally prepared at 160℃ for 12 h with ZnCl2.2H2O,InCl3,and thiourea as the starting reagents in ethanol.The morphology,structure,and phase composition of the asprepared product ...ZnIn2S4 microspheres have been solvothermally prepared at 160℃ for 12 h with ZnCl2.2H2O,InCl3,and thiourea as the starting reagents in ethanol.The morphology,structure,and phase composition of the asprepared product were characterized by means of X-ray powder diffraction(XRD),field-emission scanning electron microscopy(FE-SEM),X-ray photoelectron spectra(XPS),transmission electron microscopy(TEM),high-resolution TEM(HRTEM),and selected area electron diffraction(SAED).Results revealed that the prepared ZnIn2S4 microspheres were composed of sheetlike nanocrystals.The average diameter of the microspheres and the thickness of the nanosheets are about 1-6 μm and 10-50 nm,respectively.A possible growth mechanism of the ZnIn2S4 nanosheet-built microspheres was proposed and briefly discussed.展开更多
In this study, bismuth oxyhalide(Bi OXs(X_Cl, Br, I)) semiconductors were prepared by a simple solvothermal method, with ethanol serving as solvent and a series of tetrabutylammonium halide surfactants as halogen ...In this study, bismuth oxyhalide(Bi OXs(X_Cl, Br, I)) semiconductors were prepared by a simple solvothermal method, with ethanol serving as solvent and a series of tetrabutylammonium halide surfactants as halogen sources. Under identical synthetic conditions, Bi OBr was more readily constructed into regular flower-like hierarchical architectures. The photocatalytic properties of the materials were studied by monitoring the degradation of rhodamine B(Rh B),with visible light absorption, and colorless salicylic acid(SA). It was found that both Rh B and SA were rapidly degraded on the surface of Bi OBr. Bi OCl was rather active for the degradation of Rh B,but ineffective toward the degradation of SA. However, neither Rh B nor SA could be degraded effectively in the case of Bi OI. Further experiments such as UV–visible spectroscopy and detection of U OH and O2 Uradicals suggest that the electronic structure of the Bi OX photocatalysts is responsible for the difference in their activities.展开更多
A simple biomolecule-assisted synthetic route has been successfully developed to prepare bismuth sulfide(Bi 2 S 3 ) nanorods under solvothermal conditions.In the synthetic system,pentahydrate bismuth nitrate was emp...A simple biomolecule-assisted synthetic route has been successfully developed to prepare bismuth sulfide(Bi 2 S 3 ) nanorods under solvothermal conditions.In the synthetic system,pentahydrate bismuth nitrate was employed to supply Bi source and L-cystine was used as sulfide source and complexing agent.The morphology,structure,and phase composition of the as-prepared Bi 2 S 3 products were characterized by X-ray diffraction(XRD),energy dispersion spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),field-emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),selected area electron diffraction(SAED),and high-resolution transmission electron microscopy(HRTEM).The experimental results show that the nanorods have uniform diameter of 100-200 nm and length of 2-4 μm.The possible formation mechanism for the bismuth sulfide nanorods was discussed.展开更多
Mercury telluride (HgTe) nanoplatelets were obtained via a facile solvothermal reaction of mercury(I) chloride and tellurium powder in ethylenediamine (en). Mercury(I) was first applied as the mercury sources ...Mercury telluride (HgTe) nanoplatelets were obtained via a facile solvothermal reaction of mercury(I) chloride and tellurium powder in ethylenediamine (en). Mercury(I) was first applied as the mercury sources to prepare nanocrystal HgTe; moreover, the proposed mechanism for the fabrication of the sample was discussed in detail. The HgTe nanoplatelets were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FT-IR). The absence of IR absorption may render the title nanocrystal useful as an IR transparent material in the region.展开更多
Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(...Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(2-methyl-2-phenyl)propyltin] oxide under solvothermal conditions, and these complexes were characterized by infrared spectra, elemental analyses, and H NMR spectra. The crystal of 1 belongs to the monoclinic system, space group P21/c with a = 1.83478(19), b = 1.52707(18), c = 1.9849(2) nm, β = 122.515(7)°, Z = 4, V = 4.6896(9) nm^3, Dc = 1.324 g/cm^3, μ(MoKα) = 1.103 mm^-1, F(000) = 1952, R = 0.0697 and wR = 0.2040. In addition, thermal stability and quantum chemical calculation of 1 were also studied.展开更多
A new solvothermal post-synthesis treatment for preparing high aspect ratio magnesium aluminium layered double hydroxides(Mg Al–LDHs) has been developed. Treating laurate-intercalated Mg Al–LDHs in pure ethanol in a...A new solvothermal post-synthesis treatment for preparing high aspect ratio magnesium aluminium layered double hydroxides(Mg Al–LDHs) has been developed. Treating laurate-intercalated Mg Al–LDHs in pure ethanol in an autoclave for 48 h at 150 °C was found to produce delaminated MgA l–LDH nanosheets with a thickness of ~2.6 nm and an aspect ratio of ~105. It is proposed that the high pressure solvothermal process promotes the insertion of ethanol molecules into the LDH interlayer space, thereby facilitating delamination. This new post-synthesis treatment provides the opportunity for a facile, large scale route to highly delaminated high aspect ratio LDHs, which might be of interest towards novel nanomaterials for energy conversion and storage.展开更多
In this research, cerium (III) nitrate hexahydrate (Ce(NO3)3·6H2O) and ammonium molybdate tetrahydrate ((NH4)6Mo7O24·4H2O) with Ce3+-to-Mo6+ molar ratio of 2:3 were dissolved in 40 ml different ...In this research, cerium (III) nitrate hexahydrate (Ce(NO3)3·6H2O) and ammonium molybdate tetrahydrate ((NH4)6Mo7O24·4H2O) with Ce3+-to-Mo6+ molar ratio of 2:3 were dissolved in 40 ml different solvents of deionized (DI) water, polyethylene glycol (PEG) and ethylene glycol (EG) to form different solutions which were followed by adjusting pH from the traditional values to 7.0 and 10.0 with 1 mol.L-1 sodium hydroxide (NaOH). Subsequently, the solutions were processed by 270-W microwave-hydrother- mal/solvothermal method. Phase, morphology, vibrational modes and photonic properties were fully characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectrophotometry, ultraviolet-visible (UV-Vis) absorption and photoluminescence (PL) spectroscopy. The as-synthe-sized products were pure cerium molybdenum oxide (Ce2(MoO4)3) of nanoparticles clustered together as nano- plates in DI water and PEG solvents, and of spindle-like nanoparticles in EG solvent, including the presence of Ce-O-H mode and MoO4 units. The results show that direct energy gaps of the first two have the same value of 2.30 eV, and that of the last is 2.80 eV, including their blue emission at the same wavelength of 488 nm.展开更多
This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles (ZnO NPs): i) flower-like nanorod and nanoflakes, ii) assembled hierarchical structure, and iii...This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles (ZnO NPs): i) flower-like nanorod and nanoflakes, ii) assembled hierarchical structure, and iii) nano granule. Oleic acid (C18H3402), gluconic acid (C6H1207) and tween 80 (C64H124026) were used as surfactant/capping/reducing agent for the formation of different morphologies of nanoparticles. The as-synthesized ZnO NPs were characterized by different physicochemical techniques such as UV-vis (UV-vis) spectroscopy, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FFIR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analysis and dynamic light scattering (DLS) studies. Further, the antioxidant and antimicrobial activity of these nanostructures was evaluated. The antioxidant activity of these nanostructures was assessed via 2,2-diphenyl,1-1 picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and H202 free radical scavenging activity. The in vitro antimicrobial activity of the obtained nanostructures was demonstrated against both gram negative (Escherichia coil) and gram positive (Staphylococcus aureus) bacterial genera. This study revealed antioxidant and antimicrobial properties of different structures ofZnO NPs suggesting their biomedical and industrial applications.展开更多
A novel solvothermal synthesis method for the direct growth of B-form crystals of copper phthalocyanine(CuPc) is presented in this article. With quinoline as solvent, crystals were grown after cooling the reaction m...A novel solvothermal synthesis method for the direct growth of B-form crystals of copper phthalocyanine(CuPc) is presented in this article. With quinoline as solvent, crystals were grown after cooling the reaction mixture of 1,3-diiminoisoindoline and copper oxide, heated for 9 h at 270 ℃, to room temperature in an autoclave. These high quality crystals were suitable for characterization measurements. The single-crystal diffraction data show a monoclinic system unit cell: a=1.4668(3) nm, b=0.48109(10) nm, c=1.9515(7) nm, a=90°, B=121.04(2)°, r=90°, where the corresponding cell volume is 1.17991 nm^3. Needle-like single crystals of CuPc up to 10.5 mm in length were obtained. The influences of different temperatures, reaction time and solvent volume on the crystal yields were also discussed. Optimum reaction conditions were 10 mL of quinoline, at 270 ℃ for 8 h.展开更多
Well-shaped and uniformly dispersed LiFePOnanorods with a length of 400–500 nm and a diameter of about 100 nm, are obtained with participation of a proper amount of anion surfactant sodium dodecyl sulfonate(SDS) wi...Well-shaped and uniformly dispersed LiFePOnanorods with a length of 400–500 nm and a diameter of about 100 nm, are obtained with participation of a proper amount of anion surfactant sodium dodecyl sulfonate(SDS) without any further heating as a post-treatment. The surfactant acts as a self-assembling supermolecular template, which stimulated the crystallization of LiFePOand directed the nanoparticles growing into nanorods between bilayers of surfactant(BOS). LiFePOnanorods with the reducing crystal size along the b axis shorten the diffusion distance of Liextraction/insertion, and thus improve the electrochemical properties of LiFePOnanorods. Such prepared LiFePOnanorods exhibited excellent specific capacity and high rate capability with discharge capacity of 151 mAh/g, 122 mAh/g and 95 mAh/g at 0.1C, 1 C and 5 C, respectively. Such excellent performance of LiFePOnanorods is supposed to be ascribed to the fast Lidiffusion velocity from reduced crystal size along the b axis and the well electrochemical conductivity. The structure, morphology and electrochemical performance of the samples were characterized by XRD, FE-SEM, HRTEM, charge/discharge tests, and EIS(electrochemical impedance spectra).展开更多
基金Project(51104185)supported by the National Natural Science Foundation of ChinaProject(2010QZZD003)supported by the Key Project of Central South University of Fundamental Research Funds for the Central Universities of China
文摘In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) or N-methyl- 2-pyrrolidone(NMP) on solvothermal synthesis of [Zn4O(BDC)3]8 were investigated through a combined DFT and experimental study. XRD and SEM showed that the absorbability of NMP in the pore of [Zn4O(BDC)3]8 was weaker than that of DMF. The thermal decomposition temperature of [Zn4O(BDC)3]8 synthesized in DMF was higher than that in NMP according to TG and FT-IR. In addition, the nitrogen sorption isotherms indicated that NMP improved gas sorption property of [Zn4O(BDC)3]8. The COSMO optimized calculations indicated that the total energy of Zn4O(BDC)3 in NMP was higher than that in DMF, and compared with non-solvent system, the charge of zinc atoms decreased and the charge value was the smallest in NMP. Furthermore, the interaction of DMF, NMP or DEF in [Zn4O(BDC)3]8 crystal model was calculated by DFT method. The results suggested that NMP should be easier to be removed from pore of materials than DMF from the point of view of energy state. It can be concluded that NMP was a favorable solvent to synthesize [Zn4O(BDC)3]8 and the microscopic mechanism was that the binding force between Zn4O(BDC)3 and NMP molecule was weaker than DMF.
基金supported by the National Natural Science Foundation of China (No. 22179094)。
文摘Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resulting in its much lower sodium storage performance than hard carbon. We propose a novel preoxidation strategy to introduce additional oxygen atoms into the low-cost soft carbon precursor pitch to fabricate a defect-rich and large-interlayer spacing hard carbon anode(HPP-1100). Compared with the direct pyrolysis of pitch carbon, the sodium storage capacity of HPP-1100 is significantly improved from 120.3 m Ah/g to 306.7 m Ah/g, with an excellent rate and cycling capability(116.5 m Ah/g at 10 C). Moreover, when assorted with an O_(3)-Na(NiFeMn)1/3O_(2)cathode, the full cell delivers a high reversible capacity of 274.0 m Ah/g at 0.1 C with superb cycle life. This work provides a new solution for realizing the application of low-cost pitch anodes in Na-ion batteries.
基金financially supported by the Sichuan Province Science and Technology Support Program (No. 2014GZ0090)
文摘Aggregates of cerium dioxide nanoparticles(nano-CeO_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO_2 were systematically studied by X-ray diffraction(XRD),transmission electron microscopy(TEM), laser particle size analyzer(LA) and specific surface area and pore size analyzer during the solvothermal process. Among all the obtained samples, the 18-h solvothermal-prepared nano-CeO_2 aggregates show the best crystallinity and the largest specific surface area of 110.92 m^2·g^(-1). Owing to the high activity derived from the high specific surface area of the aggregates, the application as arsenic(As) adsorption was also studied. The adsorption efficiency of arsenic by nano-CeO_2 aggregates was established as the function of adsorbent dose, then pH value and at last adsorption time.The results indicate that the nano-CeO_2 aggregates show a high efficiency in removing arsenic from low As concentration solution, from which the nano-CeO_2 adsorbent could be easily separated. In addition, the adsorption kinetics is best fitted to pseudo-second-order model(R^2 = 0.99999).
基金financially supported by the National Natural Science Foundation of China (Nos. 21603019,51772034 and 12075224)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(No. SKL201807SIC)The Fundamental Research Funds for the Central Universities (No. 2019CDJGFCL004)。
文摘Three-dimensional(3D) ultra-tiny Fe_(2)O_(3) nanoparticles/graphene hydrogels were prepared using a facile and efficient solvothermal reaction, by which the phase of iron oxide, particle size and the morphology of hydrogels can be precisely controlled by simply adjusting the solvothermal reaction time. Accordingly, the effect of the microstructures of hydrogels on electrochemical performance was systematically studied. It was found that Fe_(2)O_(3)/r GO-50 hydrogels(with a solvothermal reaction time of 50 min) possessed a desirable crystallinity, suitable particle size, decent porous structure, large specific surface area and high electrical conductivity, thus exhibiting a superior electrochemical performance as binder-free anode of supercapacitors: a large potential range of 1.15 V, an ultrahigh specific capacitance of 1090 F·g^(-1) at a current density of 2A·g^(-1) and excellent rate capability (531 F·g^(-1) at 10 A·g^(-1)). The rational design and systematic research of electrode materials will provide new lights for the preparation of advanced electrochemical energy storage devices.
基金financially supported by the National Natural Science Foundation of China(No.51203041)the Higher School in Hebei Province Science and Technology Research Project(No.ZH201206)the Scientific Research Foundation of Ministry Education for Returned Overseas Students
文摘The well-distribution spindle Li Fe PO4(LFP)nanoparticles as cathode of lithium secondary batteries were synthesized by a solvothermal reaction route at low temperature(180 °C) in which the ascorbic acid was used as reducing agent. In order to guarantee that the p H values of thermal systems were not affected too much and the reducibility of the system was enhanced at the same time,glucose was chosen as an auxiliary reductant in this reaction. The obtained powders were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),and laser particle analyzer. The results show that the carbon-coated uniform spindle olivine Li Fe PO4/C-glucose particles(glucose as auxiliary reductant, LFP/C-G) are prepared with the size 500–600 nm and without any impurity phases. Their electrochemical properties were evaluated by electrochemical impedance spectroscopy,cyclic voltammetry, and galvanostatic charge/discharge tests. LFP/C-G has a higher conductivity and better reversible capability than carbon-coated LFP(LFP/C). The highest discharge capacity of LFP/C-G is 161.3 mAh·g-1at0.1C and 108.6 mAh·g-1at 5.0C, respectively. The results imply that the neat crystal nanostructure of LFP/C-G has excellent capacity retention and cycling stability.The adding of glucose is the key factor for the welldistribution and neat crystal structure of nanoparticles,thus the electrochemical performances of materials are improved.
基金supported by the National Natural Science Foundation of China(21172269)Innovation Group of Hubei Natural Science Foundation(2018CFA023)Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(JDGD-201809)~~
文摘Vanadium‐chromium oxides(VCrO)were usually prepared by high‐temperature solid‐state reactions;however,mixed phases were frequently produced and the morphology of the products was not well controlled.In this work,we prepared amorphous VCrO precursors by using V2O5 and CrO3 and alcohols or mixtures of alcohol and water via solvothermal reaction at 180°C.The precursors were then calcined under nitrogen at various temperatures.The products were characterized by powder X‐ray diffraction,transmission electron microscopy,and X‐ray photoelectron spectroscopy.It was revealed that pure‐phase nanocrystalline orthorhombic CrVO4 was obtained when methanol or methanol/water was used as the solvothermal medium and the precursor was calcined at 700°C.The size of the CrVO4 crystals was around 500 nm when methanol was used,whereas it reduced significantly to less than 50 nm when a mixture of methanol and water was used.The sizes could be effectively tuned from 10 to 50 nm by varying the methanol/water volume ratio.To the best of our knowledge,this is the first report on the synthesis of pure‐phase CrVO4 nanocrystals.The nano‐CrVO4 showed almost the highest catalytic activity for the ammoxidation of 2,6‐dichlorotoluene to 2,6‐dichlorobenzonitrile among the reported bi‐component composite oxides,owing to its smaller particle size,larger specific surface area,and more exposed active centers.
基金supported financially by the National Natural Science Foundation of China (No. 51572238)the Strategic Emerging Industry Project of Hunan Province, China (No. 2016GK4030)
文摘As a potential substitute for LiFePO4, LiMnPO4 has attracted more and more attention due to its higher energy, showing potential application in electric vehicle(EV) or hybrid electric vehicle(HEV). In this work,solvothermal method was used to prepare nano-sized LiMnPO4, where ethylene glycol was used as solvent, and lithium acetate(LiAc), phosphoric acid(H3 PO4) and manganese chloride(MnCl2) were used as precursors. The crystal structure and morphology of the obtained products were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performance was evaluated by charge-discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the molar ratio of LiAc:H3 PO4:MnCl2 plays a critical role in directing the morphology of LiMnPO4. Large plates transform into irregular nanoparticles when the molar ratio changes from 2:1:1 to 6:1:1. After carbon coating, the product prepared from the 6:1:1 precursor could deliver discharge capacities of 156.9,122.8, and 89.7 mAhg-1 at 0.05 C, 1 C and 10 C, respectively.The capacity retention can be maintained at 85.1% after 200 cycles at 1 C rate for this product.
文摘Hybrid composites of phosphomolybdic acid@UiO-66(PMo12@UiO-66)and Co-substituted phosphomolybdic acid@UiO-66(PMo11Co@UiO-66)were synthesized using the direct solvothermal method.A variety of characterization results demonstrated that phosphomolybdic acid(PMo12)or Co-substituted phosphomolybdate acid(PMo11Co)clusters are uniformly dispersed in the cages of Zr-based metal-organic UiO-66 frameworks.The catalytic properties of these hybrid composites were investigated by applying the epoxidation of olefins with tert-butyl hydroperoxide as the oxidant.Compared to PMo12@UiO-66,PMo11Co@UiO-66 showed a much higher catalytic activity and was simply recovered by filtration and reused for at least ten runs without significant loss of catalytic activity.Particularly,PMo11Co@UiO-66 can efficiently convert cyclic olefins like limonenes to epoxides,and its selectivity to 1,2-limonene oxide reached 91%in the presence of a radical inhibitor such as hydroquinone.The excellent catalytic activity and stability of the hybrid composite PMo11Co@UiO-66 are mainly attributed to the uniform distribution of highly active PMo11Co units within the smaller cages of UiO-66,to the suitable surface polarity of the hybrid composite for facilitating the access of reagents and solvent,and to the strong interface-interactions between the polyoxometalate and the UiO-66 framework.
基金supported by the National Nature Science Foundation of China (21303088)
文摘V2O3 nanoparticles with high surface area have been successfully prepared by a new solvothermal method without using any surfactant and template. The size of V2O3 nanoparticles is mostly equal to 10 nm-30 nm. The highest surface area of obtained V2O3 nanoparticles reaches 49 m2/g. Several kinds of V2O3 catalysts were prepared by different methods. All these V2O3 catalysts obtained thereby showed high catalytic activity for oxidative desulfurization(ODS) reaction by using tert-butyl hydroperoxide as the oxidant. The V2O3 catalyst with a highest ODS activity was obtained under the following conditions: The catalyst was prepared upon using V2O5 as the vanadium source, methanol as the solvent, and oxalic acid as the complexing reagent at a V2O5/oxalic acid molar ratio of 1:2. The process for ODS of dibenzothiophene was carried out under mild conditions(under atmospheric pressure and at a relatively low temperature). The highest ODS activity of the obtained V2O3 nanoparticles can be attributed to their highest surface area.
基金Project supported by SRF for ROCS, SEM (2003-14) and Science and Technology Department of Zhejiang Province (2003C11027)
文摘Y2O3 nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y2O3 in order to obtain better materials performance. In present study, yttrium oxyhydroxide precursor was synthesized via a facile solvothermal process through the dissolution-re-crystallization mechanism of Y2O3 raw powders in the ethylenediamine solvent, then nanosized yttrium oxide crystal was prepared from the precursor through post heat treatment process. The effects of solvothermal treatment temperature, holding time, solvent kinds and post heat treatment parameters on crystalline structure, grain shape and size of nanocrystal were investigated by XRD, TEM and TGA-DTA measurements. TEM images reveal that the morphology of product after post heat treatment at 460℃for 12 h is rice-like nanocrystal. XRD shows that this product is pure cubic Y2O3 cphase. Present study reveals that high purity Y2O3 with rice-like morphology can be easily prepared with average size around 30 nm under suitable post heat treatment parameters. In addition, the effects of solvents such as water and ethanol etc. on the crystal structure and morphology were also investigated. It is suggested that dissolution-recrystallization process may be the main mechanism for the formation of nano-sized YOOH precursors under solvothermal reaction condition, and the ethylenediamine solvent is likely to play an important role in controlling the transformation process of yttria precursors to the Y2O3 nanocrystal.
基金support of the project from the National Natural Science Foundation of China (Grant No. 50972107)
文摘ZnIn2S4 microspheres have been solvothermally prepared at 160℃ for 12 h with ZnCl2.2H2O,InCl3,and thiourea as the starting reagents in ethanol.The morphology,structure,and phase composition of the asprepared product were characterized by means of X-ray powder diffraction(XRD),field-emission scanning electron microscopy(FE-SEM),X-ray photoelectron spectra(XPS),transmission electron microscopy(TEM),high-resolution TEM(HRTEM),and selected area electron diffraction(SAED).Results revealed that the prepared ZnIn2S4 microspheres were composed of sheetlike nanocrystals.The average diameter of the microspheres and the thickness of the nanosheets are about 1-6 μm and 10-50 nm,respectively.A possible growth mechanism of the ZnIn2S4 nanosheet-built microspheres was proposed and briefly discussed.
基金supported by the National Natural Science Foundation of China (Nos. 21377067, 21177072, 21207079)Natural Science Foundation for Innovation Group of Hubei Province, China (No. 2009CDA020)open fund (KF2011-07) from the State Key Laboratory of Environmental Chemistry and Ecotoxicology, RCEES, CAS
文摘In this study, bismuth oxyhalide(Bi OXs(X_Cl, Br, I)) semiconductors were prepared by a simple solvothermal method, with ethanol serving as solvent and a series of tetrabutylammonium halide surfactants as halogen sources. Under identical synthetic conditions, Bi OBr was more readily constructed into regular flower-like hierarchical architectures. The photocatalytic properties of the materials were studied by monitoring the degradation of rhodamine B(Rh B),with visible light absorption, and colorless salicylic acid(SA). It was found that both Rh B and SA were rapidly degraded on the surface of Bi OBr. Bi OCl was rather active for the degradation of Rh B,but ineffective toward the degradation of SA. However, neither Rh B nor SA could be degraded effectively in the case of Bi OI. Further experiments such as UV–visible spectroscopy and detection of U OH and O2 Uradicals suggest that the electronic structure of the Bi OX photocatalysts is responsible for the difference in their activities.
基金support from National Natural Sciences Foundation of China (GrantNos. 50772075 and 50972107)
文摘A simple biomolecule-assisted synthetic route has been successfully developed to prepare bismuth sulfide(Bi 2 S 3 ) nanorods under solvothermal conditions.In the synthetic system,pentahydrate bismuth nitrate was employed to supply Bi source and L-cystine was used as sulfide source and complexing agent.The morphology,structure,and phase composition of the as-prepared Bi 2 S 3 products were characterized by X-ray diffraction(XRD),energy dispersion spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),field-emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),selected area electron diffraction(SAED),and high-resolution transmission electron microscopy(HRTEM).The experimental results show that the nanorods have uniform diameter of 100-200 nm and length of 2-4 μm.The possible formation mechanism for the bismuth sulfide nanorods was discussed.
基金supported by the NSF for Distinguished Young Scientist of China (20425104)Fujian Key Laboratory of Nanomaterials (2006L2005)NSF of Fujian Province (2004J039)
文摘Mercury telluride (HgTe) nanoplatelets were obtained via a facile solvothermal reaction of mercury(I) chloride and tellurium powder in ethylenediamine (en). Mercury(I) was first applied as the mercury sources to prepare nanocrystal HgTe; moreover, the proposed mechanism for the fabrication of the sample was discussed in detail. The HgTe nanoplatelets were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FT-IR). The absence of IR absorption may render the title nanocrystal useful as an IR transparent material in the region.
基金Supported by Natural Science Foundation of Hunan Province(No.13JJ3112)Scientific & Technological Projects of Hunan Province(No.2013TZ2025,2014NK3086)+3 种基金Open Foundation of Innovation Platform of Hunan Provincial University(No.13K105,14K014)Scientific & Technological Projects of Hengyang City(No.2012KJ30)Cultivation projects Based on Collaborative Innovation Center of Hengyang Normal University(No.12XT02)the Youth Backbone Teacher Training Program of Hengyang Normal University(2012)
文摘Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(2-methyl-2-phenyl)propyltin] oxide under solvothermal conditions, and these complexes were characterized by infrared spectra, elemental analyses, and H NMR spectra. The crystal of 1 belongs to the monoclinic system, space group P21/c with a = 1.83478(19), b = 1.52707(18), c = 1.9849(2) nm, β = 122.515(7)°, Z = 4, V = 4.6896(9) nm^3, Dc = 1.324 g/cm^3, μ(MoKα) = 1.103 mm^-1, F(000) = 1952, R = 0.0697 and wR = 0.2040. In addition, thermal stability and quantum chemical calculation of 1 were also studied.
基金the AdFutura Scholarship provided by the Slovene Human Resources Development and Scholarship Fund for this workthe Clarendon and Balliol Jowett Scholarships for subsequent funding+1 种基金SCG Chemicals Co., Ltd. (Thailand)SCG Packaging Co. Ltd PLC, for funding
文摘A new solvothermal post-synthesis treatment for preparing high aspect ratio magnesium aluminium layered double hydroxides(Mg Al–LDHs) has been developed. Treating laurate-intercalated Mg Al–LDHs in pure ethanol in an autoclave for 48 h at 150 °C was found to produce delaminated MgA l–LDH nanosheets with a thickness of ~2.6 nm and an aspect ratio of ~105. It is proposed that the high pressure solvothermal process promotes the insertion of ethanol molecules into the LDH interlayer space, thereby facilitating delamination. This new post-synthesis treatment provides the opportunity for a facile, large scale route to highly delaminated high aspect ratio LDHs, which might be of interest towards novel nanomaterials for energy conversion and storage.
基金financially supported by Thailand's Office of the Higher Education Commission through the National Research University Project for Chiang Mai University
文摘In this research, cerium (III) nitrate hexahydrate (Ce(NO3)3·6H2O) and ammonium molybdate tetrahydrate ((NH4)6Mo7O24·4H2O) with Ce3+-to-Mo6+ molar ratio of 2:3 were dissolved in 40 ml different solvents of deionized (DI) water, polyethylene glycol (PEG) and ethylene glycol (EG) to form different solutions which were followed by adjusting pH from the traditional values to 7.0 and 10.0 with 1 mol.L-1 sodium hydroxide (NaOH). Subsequently, the solutions were processed by 270-W microwave-hydrother- mal/solvothermal method. Phase, morphology, vibrational modes and photonic properties were fully characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectrophotometry, ultraviolet-visible (UV-Vis) absorption and photoluminescence (PL) spectroscopy. The as-synthe-sized products were pure cerium molybdenum oxide (Ce2(MoO4)3) of nanoparticles clustered together as nano- plates in DI water and PEG solvents, and of spindle-like nanoparticles in EG solvent, including the presence of Ce-O-H mode and MoO4 units. The results show that direct energy gaps of the first two have the same value of 2.30 eV, and that of the last is 2.80 eV, including their blue emission at the same wavelength of 488 nm.
文摘This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles (ZnO NPs): i) flower-like nanorod and nanoflakes, ii) assembled hierarchical structure, and iii) nano granule. Oleic acid (C18H3402), gluconic acid (C6H1207) and tween 80 (C64H124026) were used as surfactant/capping/reducing agent for the formation of different morphologies of nanoparticles. The as-synthesized ZnO NPs were characterized by different physicochemical techniques such as UV-vis (UV-vis) spectroscopy, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FFIR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analysis and dynamic light scattering (DLS) studies. Further, the antioxidant and antimicrobial activity of these nanostructures was evaluated. The antioxidant activity of these nanostructures was assessed via 2,2-diphenyl,1-1 picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and H202 free radical scavenging activity. The in vitro antimicrobial activity of the obtained nanostructures was demonstrated against both gram negative (Escherichia coil) and gram positive (Staphylococcus aureus) bacterial genera. This study revealed antioxidant and antimicrobial properties of different structures ofZnO NPs suggesting their biomedical and industrial applications.
基金the National Natural Science Foundation of China(Nos.60307002,20472014)Doctoral Foundation of Dalian University of Technology(No.893327)Young Teacher Foundation of Dalian University of Technology,China.
文摘A novel solvothermal synthesis method for the direct growth of B-form crystals of copper phthalocyanine(CuPc) is presented in this article. With quinoline as solvent, crystals were grown after cooling the reaction mixture of 1,3-diiminoisoindoline and copper oxide, heated for 9 h at 270 ℃, to room temperature in an autoclave. These high quality crystals were suitable for characterization measurements. The single-crystal diffraction data show a monoclinic system unit cell: a=1.4668(3) nm, b=0.48109(10) nm, c=1.9515(7) nm, a=90°, B=121.04(2)°, r=90°, where the corresponding cell volume is 1.17991 nm^3. Needle-like single crystals of CuPc up to 10.5 mm in length were obtained. The influences of different temperatures, reaction time and solvent volume on the crystal yields were also discussed. Optimum reaction conditions were 10 mL of quinoline, at 270 ℃ for 8 h.
基金financially sponsored by the National Natural Science Foundation of China(Grant No:91534205)
文摘Well-shaped and uniformly dispersed LiFePOnanorods with a length of 400–500 nm and a diameter of about 100 nm, are obtained with participation of a proper amount of anion surfactant sodium dodecyl sulfonate(SDS) without any further heating as a post-treatment. The surfactant acts as a self-assembling supermolecular template, which stimulated the crystallization of LiFePOand directed the nanoparticles growing into nanorods between bilayers of surfactant(BOS). LiFePOnanorods with the reducing crystal size along the b axis shorten the diffusion distance of Liextraction/insertion, and thus improve the electrochemical properties of LiFePOnanorods. Such prepared LiFePOnanorods exhibited excellent specific capacity and high rate capability with discharge capacity of 151 mAh/g, 122 mAh/g and 95 mAh/g at 0.1C, 1 C and 5 C, respectively. Such excellent performance of LiFePOnanorods is supposed to be ascribed to the fast Lidiffusion velocity from reduced crystal size along the b axis and the well electrochemical conductivity. The structure, morphology and electrochemical performance of the samples were characterized by XRD, FE-SEM, HRTEM, charge/discharge tests, and EIS(electrochemical impedance spectra).