The exothermic chemical reaction of CaCl2 (calcium chloride) with NH3 (ammonia) can be utilized as an energy storage system. Since this reaction is a typical gas-solid reaction, the reaction rate is controlled by the ...The exothermic chemical reaction of CaCl2 (calcium chloride) with NH3 (ammonia) can be utilized as an energy storage system. Since this reaction is a typical gas-solid reaction, the reaction rate is controlled by the heat transfer rate. In order to improve the low heat transfer rate of the ammoniation and the deammoniation of CaCl2, the influence of a heat transfer media (Ti: titanium) on the heat transfer rate of the solid ammoniated salt (CaCl2.mNH3) was studied and tested experimentally. The performance tests were carried out under the conditions of various weight ratios of Ti. No decrease of the activation of chemical reaction and no corrosion of experimental apparatus were observed on the repeated runs (≥30 times each). The heat transfer rate of ammoniated salt was greatly improved by adding Ti under the constant pressure (0.5 MPa). The reaction time required for the ammoniation of CaCl2 mixed with Ti was approximately 16% - 54% shorter than that of CaCl2 alone, and the reaction time required for the deammoniation was also approximately 19% - 59% shorter than that of CaCl2 alone.展开更多
Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydroge...Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydrogenation at T≥900℃ remarkably enhanced the UV photocatalytic ability of STO, but the visible-light photocatalysis was still unavailable, while ammoniation at T≥800℃ introduced the N doping, resulting in visible-light photocat- alytie activity. Furthermore, when a hydrogenated STO was subjected to ammoniation, the visible-light photocatalytie ability was nearly the same as that of the ammoniated one; but the hydrogenation of an ammoniated one significantly enhanced visible-light photoeatalysis, indicating a synergetic effect of hydrogenation and ammoniation. Discussions and identifications have been made to analyze these results.展开更多
The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corros...The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corrosion and coking to prolong the operation period, to increase the yield of adiponitrile and to improve the design of the reactor. Macrokinetic equations of ammoniation-neutralization of adipic acid and dehydration were of first-order to adipic concentration cB≥3.5% and of second order for cB≥3.5%. Catalyst H3PO4 reduced the activation energy of neutralization and dehydration reactions of adipic acid and was significantly important for the second step of dehydration to produce adiponitrile.展开更多
The nitrogen modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH + 4 N was released, NO - 3 N concentration was decreased and total nitrogen loss was blocked wi...The nitrogen modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH + 4 N was released, NO - 3 N concentration was decreased and total nitrogen loss was blocked within incubation period. During releasing nitrogen from the metabolism of NML, white rot fungus cometabolized recalcitrant environmental pollutants and showed higher degradation capability. Results indicated that this NML complex colonized by white rot fungus might be effective with economic feasibility when they are applied into the vast field ecosystem, it might stabilize NH + 4 nitrogen flux and bioremediate the polluted environmental sites.展开更多
Flower-shape clustering GaN nanorods are successfully synthesized on Si（111） substrates through ammoniating Ga2O3/ZnO films at 950℃. The as-grown products are characterized by x-ray diffraction （XRD）, scanning el...Flower-shape clustering GaN nanorods are successfully synthesized on Si（111） substrates through ammoniating Ga2O3/ZnO films at 950℃. The as-grown products are characterized by x-ray diffraction （XRD）, scanning electron microscope （SEM）, field-emission transmission electron microscope （FETEM）, Fourier transform infrared spectrum （FTIR） and fluorescence spectrophotometer. The SEM images demonstrate that the products consist of flower-shape clustering GaN nanorods. The XRD indicates that the reflections of the samples can be indexed to the hexagonal GaN phase and HRTEM shows that the nanorods are of pure hexagonal GaN single crystal. The photoluminescence （PL） spectrum indicates that the GaN nanorods have a good emission property. The growth mechanism is also briefly discussed.展开更多
Searching for novel solid electrolytes is of great importance and challenge for all-solid-state Mg batteries.In this work,we develop an amorphous Mg borohydride ammoniate,Mg(BH_(4))_(2)·2NH_(3),as a solid Mg elec...Searching for novel solid electrolytes is of great importance and challenge for all-solid-state Mg batteries.In this work,we develop an amorphous Mg borohydride ammoniate,Mg(BH_(4))_(2)·2NH_(3),as a solid Mg electrolyte that prepared by a NH_(3)redistribution between 3D framework-γ-Mg(BH_(4))_(2)and Mg(BH_(4))_(2)·6NH_(3).Amorphous Mg(BH_(4))_(2)·2NH_(3)exhibits a high Mg-ion conductivity of 5×10^(-4)S cm^(-1)at 75℃,which is attributed to the fast migration of abundant Mg vacancies according to the theoretical calculations.Moreover,amorphous Mg(BH_(4))_(2)·2NH_(3)shows an apparent electrochemical stability window of 0-1.4 V with the help of in-situ formed interphases,which can prevent further side reactions without hindering the Mg-ion transfer.Based on the above superiorities,amorphous Mg(BH_(4))_(2)·2NH_(3)enables the stable cycling of all-solid-state Mg cells,as the critical current density reaches 3.2 mA cm^(-2)for Mg symmetrical cells and the reversible specific capacity reaches 141 mAh g^(-1)with a coulombic efficiency of 91.7%(first cycle)for Mg||TiS_(2)cells.展开更多
Metal borohydride ammoniates have become one of the most promising hydrogen storage materials due to their ultrahigh capacities.However,their application is still restricted by the high temperature of hydrogen desorpt...Metal borohydride ammoniates have become one of the most promising hydrogen storage materials due to their ultrahigh capacities.However,their application is still restricted by the high temperature of hydrogen desorption and the release of ammonia.Here,to promote the dehydrogenation evolution and suppress the ammonia release,different amounts of NbF 5 were introduced into Mg(BH4)2·2NH3.Compared to the pure Mg(BH_(4))_(2)·2NH_(3),the Mg(BH_(4))_(2)·2NH_(3)-NbF_(5) composites exhibit lower onset dehydriding temperatures(53–57℃)and higher dehydriding capacities(5.6 wt.%–8.2 wt.%)at below 200℃,with the complete suppression of ammonia.In addition,7.4 wt.%H_(2) could be released from Mg(BH_(4))_(2)·2NH_(3)–5 mol%NbF5 composite at 200℃ within 20 min and the apparent activation energy is calculated to be 60.28 kJ mol^(-1),which is much lower than that of pure Mg(BH_(4))_(2)·2NH_(3)(92.04 kJ mol^(-1)).Mg(BH_(4))_(2)·2NH_(3) should mechanochemically react with NbF5,forming dual-metal(Mg,Nb)borohydride ammoniate and spherical MgF2.The introduction of electronegative Nb cation results in-situ formation of(Mg,Nb)borohydride ammoniate towards a lower dehydrogenation temperature and a higher hydrogen release purity.The increased phase boundaries among the Mg(BH_(4))_(2)·2NH_(3),dual-metal(Mg,Nb)borohydride ammoniate,and MgF2 phases further facilitate the hydrogen diffusion during the dehydrogenation of the composites.展开更多
Rechargeable sodium metal batteries constitute a cost-effective option for energy storage although sodium shows some drawbacks in terms of reactivity with organic solvents and dendritic growth.Here we demonstrate that...Rechargeable sodium metal batteries constitute a cost-effective option for energy storage although sodium shows some drawbacks in terms of reactivity with organic solvents and dendritic growth.Here we demonstrate that an organic dye,indanthrone blue,behaves as an efficient cathode material for the development of secondary sodium metal batteries when combined with novel inorganic electrolytes.These electrolytes are ammonia solvates,known as liquid ammoniates,which can be formulated as NaI·3.3NH_(3) and NaBF_(4)·2.5NH_(3).They impart excellent stability to sodium metal,and they favor sodium non-dendritic growth linked to their exceedingly high sodium ion concentration.This advantage is complemented by a high specific conductivity.The battery described here can last hundreds of cycles at 10 C while keeping a Coulombic efficiency of 99%from the first cycle.Because of the high capacity of the cathode and the superior physicochemical properties of the electrolytes,the battery can reach a specific energy value as high as 210 W h kgIB^(-1),and a high specific power of 2.2 kW kgIB^(-1),even at below room temperature(4℃).Importantly,the battery is based on abundant and cost-effective materials,bearing promise for its application in large-scale energy storage.展开更多
In order to measure the thermophysical properties of ammoniated salt (CaCl2.mNH3: m = 4, 8) as an energy storage system utilizing natural resources, the measurement unit was developed, and the thermophysical propertie...In order to measure the thermophysical properties of ammoniated salt (CaCl2.mNH3: m = 4, 8) as an energy storage system utilizing natural resources, the measurement unit was developed, and the thermophysical properties (effective thermal conductivity and thermal diffusivity) of CaCl2.mNH3 and CaCl2.mNH3 with heat transfer media (Ti: titanium) were measured by the any heating method. The effective thermal conductivities of CaCl2.4NH3 + Ti and CaCl2.8NH3 + Ti were 0.14 - 0.17 and 0.18 - 0.20 W/(m.K) in the measuring temperature range of 290 - 350 K, respectively, and these values were approximately 1.5 - 2.2 times larger than those of CaCl2.4NH3 and CaCl2.8NH3. The effective thermal diffusivities were 0.22 - 0.24 × 10-6 and 0.18 - 0.19 × 10-6 m2/sin the measuring temperature range of 290 - 350 K, respectively, and these values were approximately 1.3 - 1.5 times larger than those of CaCl2.4NH3 and CaCl2.8NH3. The obtained results show that the thermophysical properties have a dependence on the bulk densities and specific heats of CaCl2.mNH3 and CaCl2.mNH3 + Ti. It reveals that the thermophysical properties in this measurement would be the valuable design factors to develop energy and H2 storage systems utilizing natural resources such as solar energy.展开更多
Hexagonal GaN nanorods are synthesized on quartz substrates through ammoniating Ga 2O 3 thin films deposited by radio frequency magnetron sputtering.X ray diffraction (XRD),scanning electron microscopy (SEM),high ...Hexagonal GaN nanorods are synthesized on quartz substrates through ammoniating Ga 2O 3 thin films deposited by radio frequency magnetron sputtering.X ray diffraction (XRD),scanning electron microscopy (SEM),high resolution transmission electron microscopy (HRTEM),and photoluminescence (PL) are used to analyze the synthesized GaN nanorods.Among the products,one dimensional GaN nanostructures owning protuberances on the surface are detected,which show interesting herringbone morphology.The analysis reveals that the herringbone GaN nanorods are polycrystalline composed of overlapping parallelepiped GaN nanocrystals arranged along the major axis.The large blue shift of yellow PL luminescence of the nanorods is observed at room temperature.展开更多
文摘The exothermic chemical reaction of CaCl2 (calcium chloride) with NH3 (ammonia) can be utilized as an energy storage system. Since this reaction is a typical gas-solid reaction, the reaction rate is controlled by the heat transfer rate. In order to improve the low heat transfer rate of the ammoniation and the deammoniation of CaCl2, the influence of a heat transfer media (Ti: titanium) on the heat transfer rate of the solid ammoniated salt (CaCl2.mNH3) was studied and tested experimentally. The performance tests were carried out under the conditions of various weight ratios of Ti. No decrease of the activation of chemical reaction and no corrosion of experimental apparatus were observed on the repeated runs (≥30 times each). The heat transfer rate of ammoniated salt was greatly improved by adding Ti under the constant pressure (0.5 MPa). The reaction time required for the ammoniation of CaCl2 mixed with Ti was approximately 16% - 54% shorter than that of CaCl2 alone, and the reaction time required for the deammoniation was also approximately 19% - 59% shorter than that of CaCl2 alone.
文摘Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydrogenation at T≥900℃ remarkably enhanced the UV photocatalytic ability of STO, but the visible-light photocatalysis was still unavailable, while ammoniation at T≥800℃ introduced the N doping, resulting in visible-light photocat- alytie activity. Furthermore, when a hydrogenated STO was subjected to ammoniation, the visible-light photocatalytie ability was nearly the same as that of the ammoniated one; but the hydrogenation of an ammoniated one significantly enhanced visible-light photoeatalysis, indicating a synergetic effect of hydrogenation and ammoniation. Discussions and identifications have been made to analyze these results.
文摘The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corrosion and coking to prolong the operation period, to increase the yield of adiponitrile and to improve the design of the reactor. Macrokinetic equations of ammoniation-neutralization of adipic acid and dehydration were of first-order to adipic concentration cB≥3.5% and of second order for cB≥3.5%. Catalyst H3PO4 reduced the activation energy of neutralization and dehydration reactions of adipic acid and was significantly important for the second step of dehydration to produce adiponitrile.
文摘The nitrogen modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH + 4 N was released, NO - 3 N concentration was decreased and total nitrogen loss was blocked within incubation period. During releasing nitrogen from the metabolism of NML, white rot fungus cometabolized recalcitrant environmental pollutants and showed higher degradation capability. Results indicated that this NML complex colonized by white rot fungus might be effective with economic feasibility when they are applied into the vast field ecosystem, it might stabilize NH + 4 nitrogen flux and bioremediate the polluted environmental sites.
基金Project supported by the State Key Program of the National Natural Science Foundation of China （Grant No 90201025） and the National Natural Science Foundation of China （Grant No 90301002）.
文摘Flower-shape clustering GaN nanorods are successfully synthesized on Si（111） substrates through ammoniating Ga2O3/ZnO films at 950℃. The as-grown products are characterized by x-ray diffraction （XRD）, scanning electron microscope （SEM）, field-emission transmission electron microscope （FETEM）, Fourier transform infrared spectrum （FTIR） and fluorescence spectrophotometer. The SEM images demonstrate that the products consist of flower-shape clustering GaN nanorods. The XRD indicates that the reflections of the samples can be indexed to the hexagonal GaN phase and HRTEM shows that the nanorods are of pure hexagonal GaN single crystal. The photoluminescence （PL） spectrum indicates that the GaN nanorods have a good emission property. The growth mechanism is also briefly discussed.
基金the support of the National Natural Science Foundation of China(51971146,51971147,52171218 and 52271222)the Shanghai Municipal Science and Technology Commission(21010503100)+3 种基金the Major Program for the Scientific Research Innovation Plan of Shanghai Education Commission(2019-01-07-00-07E00015)the Shanghai Outstanding Academic Leaders Plan,the Guangxi Key Laboratory of Information Materials(Guilin University of Electronic Technology,201017-K)the Shanghai Rising-Star Program(20QA1407100)the General Program of Natural Science Foundation of Shanghai(20ZR1438400)
文摘Searching for novel solid electrolytes is of great importance and challenge for all-solid-state Mg batteries.In this work,we develop an amorphous Mg borohydride ammoniate,Mg(BH_(4))_(2)·2NH_(3),as a solid Mg electrolyte that prepared by a NH_(3)redistribution between 3D framework-γ-Mg(BH_(4))_(2)and Mg(BH_(4))_(2)·6NH_(3).Amorphous Mg(BH_(4))_(2)·2NH_(3)exhibits a high Mg-ion conductivity of 5×10^(-4)S cm^(-1)at 75℃,which is attributed to the fast migration of abundant Mg vacancies according to the theoretical calculations.Moreover,amorphous Mg(BH_(4))_(2)·2NH_(3)shows an apparent electrochemical stability window of 0-1.4 V with the help of in-situ formed interphases,which can prevent further side reactions without hindering the Mg-ion transfer.Based on the above superiorities,amorphous Mg(BH_(4))_(2)·2NH_(3)enables the stable cycling of all-solid-state Mg cells,as the critical current density reaches 3.2 mA cm^(-2)for Mg symmetrical cells and the reversible specific capacity reaches 141 mAh g^(-1)with a coulombic efficiency of 91.7%(first cycle)for Mg||TiS_(2)cells.
基金supported by the National Key Research and Development Plan(Grant No.2021YFB3802400)the National Natural Science Foundation of China(Grant Nos.52071141,52271212,52201250)+1 种基金the Equipment Pre-research Field Foundation(Grant No.6140721040101)the Interdisciplinary Innovation Program of North China Electric Power University(Grant No.XM2112355).
文摘Metal borohydride ammoniates have become one of the most promising hydrogen storage materials due to their ultrahigh capacities.However,their application is still restricted by the high temperature of hydrogen desorption and the release of ammonia.Here,to promote the dehydrogenation evolution and suppress the ammonia release,different amounts of NbF 5 were introduced into Mg(BH4)2·2NH3.Compared to the pure Mg(BH_(4))_(2)·2NH_(3),the Mg(BH_(4))_(2)·2NH_(3)-NbF_(5) composites exhibit lower onset dehydriding temperatures(53–57℃)and higher dehydriding capacities(5.6 wt.%–8.2 wt.%)at below 200℃,with the complete suppression of ammonia.In addition,7.4 wt.%H_(2) could be released from Mg(BH_(4))_(2)·2NH_(3)–5 mol%NbF5 composite at 200℃ within 20 min and the apparent activation energy is calculated to be 60.28 kJ mol^(-1),which is much lower than that of pure Mg(BH_(4))_(2)·2NH_(3)(92.04 kJ mol^(-1)).Mg(BH_(4))_(2)·2NH_(3) should mechanochemically react with NbF5,forming dual-metal(Mg,Nb)borohydride ammoniate and spherical MgF2.The introduction of electronegative Nb cation results in-situ formation of(Mg,Nb)borohydride ammoniate towards a lower dehydrogenation temperature and a higher hydrogen release purity.The increased phase boundaries among the Mg(BH_(4))_(2)·2NH_(3),dual-metal(Mg,Nb)borohydride ammoniate,and MgF2 phases further facilitate the hydrogen diffusion during the dehydrogenation of the composites.
基金developed in the context of project RTI2018–102061–B–I00 financed by FEDER/Ministerio de Ciencia e Innovación-Agencia Estatal de InvestigaciónThe Generalitat Valenciana through project PROMETEO/2020/089 is also gratefully acknowledged。
文摘Rechargeable sodium metal batteries constitute a cost-effective option for energy storage although sodium shows some drawbacks in terms of reactivity with organic solvents and dendritic growth.Here we demonstrate that an organic dye,indanthrone blue,behaves as an efficient cathode material for the development of secondary sodium metal batteries when combined with novel inorganic electrolytes.These electrolytes are ammonia solvates,known as liquid ammoniates,which can be formulated as NaI·3.3NH_(3) and NaBF_(4)·2.5NH_(3).They impart excellent stability to sodium metal,and they favor sodium non-dendritic growth linked to their exceedingly high sodium ion concentration.This advantage is complemented by a high specific conductivity.The battery described here can last hundreds of cycles at 10 C while keeping a Coulombic efficiency of 99%from the first cycle.Because of the high capacity of the cathode and the superior physicochemical properties of the electrolytes,the battery can reach a specific energy value as high as 210 W h kgIB^(-1),and a high specific power of 2.2 kW kgIB^(-1),even at below room temperature(4℃).Importantly,the battery is based on abundant and cost-effective materials,bearing promise for its application in large-scale energy storage.
文摘In order to measure the thermophysical properties of ammoniated salt (CaCl2.mNH3: m = 4, 8) as an energy storage system utilizing natural resources, the measurement unit was developed, and the thermophysical properties (effective thermal conductivity and thermal diffusivity) of CaCl2.mNH3 and CaCl2.mNH3 with heat transfer media (Ti: titanium) were measured by the any heating method. The effective thermal conductivities of CaCl2.4NH3 + Ti and CaCl2.8NH3 + Ti were 0.14 - 0.17 and 0.18 - 0.20 W/(m.K) in the measuring temperature range of 290 - 350 K, respectively, and these values were approximately 1.5 - 2.2 times larger than those of CaCl2.4NH3 and CaCl2.8NH3. The effective thermal diffusivities were 0.22 - 0.24 × 10-6 and 0.18 - 0.19 × 10-6 m2/sin the measuring temperature range of 290 - 350 K, respectively, and these values were approximately 1.3 - 1.5 times larger than those of CaCl2.4NH3 and CaCl2.8NH3. The obtained results show that the thermophysical properties have a dependence on the bulk densities and specific heats of CaCl2.mNH3 and CaCl2.mNH3 + Ti. It reveals that the thermophysical properties in this measurement would be the valuable design factors to develop energy and H2 storage systems utilizing natural resources such as solar energy.
文摘Hexagonal GaN nanorods are synthesized on quartz substrates through ammoniating Ga 2O 3 thin films deposited by radio frequency magnetron sputtering.X ray diffraction (XRD),scanning electron microscopy (SEM),high resolution transmission electron microscopy (HRTEM),and photoluminescence (PL) are used to analyze the synthesized GaN nanorods.Among the products,one dimensional GaN nanostructures owning protuberances on the surface are detected,which show interesting herringbone morphology.The analysis reveals that the herringbone GaN nanorods are polycrystalline composed of overlapping parallelepiped GaN nanocrystals arranged along the major axis.The large blue shift of yellow PL luminescence of the nanorods is observed at room temperature.
