In order to apply lithium hydroxide(LiOH)as a low temperature chemical heat storage material,the carbonation reaction of LiOH and the prevention method are focused in this research.The carbonation of raw LiOH at stora...In order to apply lithium hydroxide(LiOH)as a low temperature chemical heat storage material,the carbonation reaction of LiOH and the prevention method are focused in this research.The carbonation of raw LiOH at storage and hydration condition is experimentally investigated.The results show that the carbonation reaction of LiOH with carbon dioxide(CO_(2))is confirmed during the hydration reaction.The carbonation of LiOH can be easily carried out with CO_(2) at room temperature and humidity.LiOH can be carbonated at a humidity range of 10%to 20%,a normal humidity region that air can easily be reached.Furthermore,the carbonation reaction rate has not nearly affected by the increase of reaction temperature.An improved storage method by storing LiOH at a low humidity less than 1.0%can be effectively prevented the carbonation of LiOH.The hydration reaction ratio of LiOH at the improved storage method shows a better result compared to the ordinary storage method.Therefore,the humidity should be carefully controlled during the storage of LiOH before hydration and dehydration reaction when apply LiOH as a low heat chemical storage material.展开更多
本文通过微波法超快速制备了泡沫镍(NF)负载的Co/Zn复合氧化物(Co-Zn/NF)。XRD测试表明生成的Co/Zn复合氧化物具有低结晶度。采用线性扫描伏安法(LSV)测试了Co-Zn/NF在碱性条件下的电催化硫离子氧化性能。与泡沫镍负载的单金属氧化物(Co...本文通过微波法超快速制备了泡沫镍(NF)负载的Co/Zn复合氧化物(Co-Zn/NF)。XRD测试表明生成的Co/Zn复合氧化物具有低结晶度。采用线性扫描伏安法(LSV)测试了Co-Zn/NF在碱性条件下的电催化硫离子氧化性能。与泡沫镍负载的单金属氧化物(Co/NF和Zn/NF)相比,Co-Zn/NF表现出更好的催化性能。在含有1 mol·L^(-1)Na2S和1 mol·L^(-1)NaOH的电解液中,Co-Zn/NF达到100 m A·cm^(-2)的电流密度所需的电位仅为0.28 V vs RHE,并且在恒定100 m A·cm^(-2)的电流密度下,长时间工作35小时后仍保持高的催化性能。此外,组装非对称电解槽(阳极:硫离子氧化反应(sulfion oxidation reaction,SOR)用1 mol·L^(-1)Na2S和1mol·L^(-1)NaOH为电解质,阴极:析氢反应(hydrogen evolution reaction,HER)用1 mol·L^(-1)Na OH为电解质)进行双电极硫氧化辅助电解水制氢测试,与传统的碱性电解水相比,达到100 m A·cm^(-2)电流密度所需的能耗降低了46%。本工作为低能耗电化学制氢提供了一种新思路,并证明了SOR耦合HER电解水制氢具有实际应用的可行性。展开更多
A novel and simple one-step, solid state reaction of multicomponent systems has been developed to synthesize cyclopentadienyl-containing organolanthanide complexes, in which the effects of the coordinated solvent mole...A novel and simple one-step, solid state reaction of multicomponent systems has been developed to synthesize cyclopentadienyl-containing organolanthanide complexes, in which the effects of the coordinated solvent molecules and the nature of the reactants were also studied. We also studied the solid state decomposition reaction of Cp2YbPz(HPz), and the formation of [CpYb(Pz)2]2 may indicate that the constrained environment in solid state can lead to a novel chemical transformation, with product selectivity possibly different from that in the liquid phase.展开更多
In this paper, submicro-scaled YF3 particles with uniform rice-like morphologies were facilely synthesized by reacting yttrium nitrate with tetrabutylammonium fluoride via a solid-state reaction process at 50 °C ...In this paper, submicro-scaled YF3 particles with uniform rice-like morphologies were facilely synthesized by reacting yttrium nitrate with tetrabutylammonium fluoride via a solid-state reaction process at 50 °C for 12 h.The phase confirmation and morphology of the as-prepared YF3 particles were investigated by X-ray powder diffraction（XRD） and scanning electron microscopy（SEM）.SEM results reveal that the YF3 submicroparticles are about 700 nm in length and 260 nm in width. Eu^3＋ and Tb^3＋ doped YF3 submicroparticles were also prepared with similar process and their photoluminescence properties were studied. Results demonstrate that the doping of Eu^3＋ and Tb^3＋ has slight effect on the morphologies of the product. Owing to the small average crystallite size or the low crystallinity of the product, the photoluminescence intensity of the Eu^3＋ and Tb^3＋ doped YF3 submicroparticles is very weak. Some characteristic peaks even cannot be observed in the emission spectrum.展开更多
Nanophase LiCoO 2 was synthesized by solid state reaction with low heating temperature, i.e. the reactants Co(Ac) 2·4H 2O and LiOH·H 2O in the appropriate molar ratio(1∶1) were mixed and ground in agate mor...Nanophase LiCoO 2 was synthesized by solid state reaction with low heating temperature, i.e. the reactants Co(Ac) 2·4H 2O and LiOH·H 2O in the appropriate molar ratio(1∶1) were mixed and ground in agate mortar, then calcined. The samples obtained were characterized by XRD and IR methods. The phenomena during synthesizing are discussed by TG/TDA analysis, and the optimum temperature of heating was chosen. The BET and ICP results suggest that the sample has a large specific surface(54.29 m 2/g), a low quantity of impurity, thus it may be a good battery material. The nanophase LiCoO 2 samples produced have good cyclic performance and a higher working voltage plateau(3.9 V).展开更多
The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O,and Na2CO3·10H2O as raw materials.The nanocrystalline ZrO2 was obtained by calcining the precursor....The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O,and Na2CO3·10H2O as raw materials.The nanocrystalline ZrO2 was obtained by calcining the precursor.The precursor and its calcined products were characterized using TG/DTA,FT-IR,XRD,and SEM.The results showed that the precursor dried at 353 K was a zirconyl carbonate compound.When the precursor was calcined at 673 K for 150min,highly crystallization ZrO2 with tetragonal structure (space group P42/nmc (137)) was obtained with a crystallite size of 24 nm.However,when the precursor was calcined at 1023 K for 150min,highly crystallization ZrO2 with monoclinic structure (space group P21/c (14)) was obtained with a crystallite size of 20 nm.The mechanism and kinetics of the thermal process of the precursor were studied using DTA and XRD techniques.Based on the Kissinger and Arrhenius equation,the values of the activation energies associated with the thermal process of the precursor were determined to be 26.80 and 566.73 kJ·mol-1 for the first and third steps,respectively.The mechanism of ZrO2 phase transition from tetragonal to monoclinic structure is the random nucleation and growth of nuclei reaction.展开更多
基金This work was supported by“Knowledge Hub Aichi,”Priority Research Project from Aichi Prefectural Government,Japan,Leading Key Projects of Chinese Academy of Sciences(No.QYZDYSSW-JSC038)Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory,Guangzhou(GML2019ZD0108)Science and Technology Planning Project of Guangdong Province,China(No.2017A050501046).
文摘In order to apply lithium hydroxide(LiOH)as a low temperature chemical heat storage material,the carbonation reaction of LiOH and the prevention method are focused in this research.The carbonation of raw LiOH at storage and hydration condition is experimentally investigated.The results show that the carbonation reaction of LiOH with carbon dioxide(CO_(2))is confirmed during the hydration reaction.The carbonation of LiOH can be easily carried out with CO_(2) at room temperature and humidity.LiOH can be carbonated at a humidity range of 10%to 20%,a normal humidity region that air can easily be reached.Furthermore,the carbonation reaction rate has not nearly affected by the increase of reaction temperature.An improved storage method by storing LiOH at a low humidity less than 1.0%can be effectively prevented the carbonation of LiOH.The hydration reaction ratio of LiOH at the improved storage method shows a better result compared to the ordinary storage method.Therefore,the humidity should be carefully controlled during the storage of LiOH before hydration and dehydration reaction when apply LiOH as a low heat chemical storage material.
文摘本文通过微波法超快速制备了泡沫镍(NF)负载的Co/Zn复合氧化物(Co-Zn/NF)。XRD测试表明生成的Co/Zn复合氧化物具有低结晶度。采用线性扫描伏安法(LSV)测试了Co-Zn/NF在碱性条件下的电催化硫离子氧化性能。与泡沫镍负载的单金属氧化物(Co/NF和Zn/NF)相比,Co-Zn/NF表现出更好的催化性能。在含有1 mol·L^(-1)Na2S和1 mol·L^(-1)NaOH的电解液中,Co-Zn/NF达到100 m A·cm^(-2)的电流密度所需的电位仅为0.28 V vs RHE,并且在恒定100 m A·cm^(-2)的电流密度下,长时间工作35小时后仍保持高的催化性能。此外,组装非对称电解槽(阳极:硫离子氧化反应(sulfion oxidation reaction,SOR)用1 mol·L^(-1)Na2S和1mol·L^(-1)NaOH为电解质,阴极:析氢反应(hydrogen evolution reaction,HER)用1 mol·L^(-1)Na OH为电解质)进行双电极硫氧化辅助电解水制氢测试,与传统的碱性电解水相比,达到100 m A·cm^(-2)电流密度所需的能耗降低了46%。本工作为低能耗电化学制氢提供了一种新思路,并证明了SOR耦合HER电解水制氢具有实际应用的可行性。
基金This work was supported by the National Natural Science Foundation of China(Grunt No.20172013)the Rescarch Funds of Excellent Young Teacher and the New Century Distinguished Scientist of the Ministry of Education of China.
文摘A novel and simple one-step, solid state reaction of multicomponent systems has been developed to synthesize cyclopentadienyl-containing organolanthanide complexes, in which the effects of the coordinated solvent molecules and the nature of the reactants were also studied. We also studied the solid state decomposition reaction of Cp2YbPz(HPz), and the formation of [CpYb(Pz)2]2 may indicate that the constrained environment in solid state can lead to a novel chemical transformation, with product selectivity possibly different from that in the liquid phase.
基金financially supported by the National Natural Science Foundation of China (Nos. 21201089 and 21261010)the Natural Science Foundation of Jiangxi Province (No. 2010BJB01100)+1 种基金the Project of Scientific and Technological Planning of Education Office of Jiangxi Province (No. GJJ11382)the Opening Fund of Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University (No. KLCBTCMR2011-04)
文摘In this paper, submicro-scaled YF3 particles with uniform rice-like morphologies were facilely synthesized by reacting yttrium nitrate with tetrabutylammonium fluoride via a solid-state reaction process at 50 °C for 12 h.The phase confirmation and morphology of the as-prepared YF3 particles were investigated by X-ray powder diffraction（XRD） and scanning electron microscopy（SEM）.SEM results reveal that the YF3 submicroparticles are about 700 nm in length and 260 nm in width. Eu^3＋ and Tb^3＋ doped YF3 submicroparticles were also prepared with similar process and their photoluminescence properties were studied. Results demonstrate that the doping of Eu^3＋ and Tb^3＋ has slight effect on the morphologies of the product. Owing to the small average crystallite size or the low crystallinity of the product, the photoluminescence intensity of the Eu^3＋ and Tb^3＋ doped YF3 submicroparticles is very weak. Some characteristic peaks even cannot be observed in the emission spectrum.
文摘Nanophase LiCoO 2 was synthesized by solid state reaction with low heating temperature, i.e. the reactants Co(Ac) 2·4H 2O and LiOH·H 2O in the appropriate molar ratio(1∶1) were mixed and ground in agate mortar, then calcined. The samples obtained were characterized by XRD and IR methods. The phenomena during synthesizing are discussed by TG/TDA analysis, and the optimum temperature of heating was chosen. The BET and ICP results suggest that the sample has a large specific surface(54.29 m 2/g), a low quantity of impurity, thus it may be a good battery material. The nanophase LiCoO 2 samples produced have good cyclic performance and a higher working voltage plateau(3.9 V).
基金financially supported by the National Natural Scientific Foundation of China (No.201161002)
文摘The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O,and Na2CO3·10H2O as raw materials.The nanocrystalline ZrO2 was obtained by calcining the precursor.The precursor and its calcined products were characterized using TG/DTA,FT-IR,XRD,and SEM.The results showed that the precursor dried at 353 K was a zirconyl carbonate compound.When the precursor was calcined at 673 K for 150min,highly crystallization ZrO2 with tetragonal structure (space group P42/nmc (137)) was obtained with a crystallite size of 24 nm.However,when the precursor was calcined at 1023 K for 150min,highly crystallization ZrO2 with monoclinic structure (space group P21/c (14)) was obtained with a crystallite size of 20 nm.The mechanism and kinetics of the thermal process of the precursor were studied using DTA and XRD techniques.Based on the Kissinger and Arrhenius equation,the values of the activation energies associated with the thermal process of the precursor were determined to be 26.80 and 566.73 kJ·mol-1 for the first and third steps,respectively.The mechanism of ZrO2 phase transition from tetragonal to monoclinic structure is the random nucleation and growth of nuclei reaction.
