Planar Na ion micro-supercapacitors(NIMSCs) that offer both high energy density and power density are deemed to a promising class of miniaturized power sources for wearable and portable microelectron-ics. Nevertheless...Planar Na ion micro-supercapacitors(NIMSCs) that offer both high energy density and power density are deemed to a promising class of miniaturized power sources for wearable and portable microelectron-ics. Nevertheless, the development of NIMSCs are hugely impeded by the low capacity and sluggish Na ion kinetics in the negative electrode.Herein, we demonstrate a novel carbon-coated Nb_(2)O_5 microflower with a hierarchical structure composed of vertically intercrossed and porous nanosheets, boosting Na ion storage performance. The unique structural merits, including uniform carbon coating, ultrathin nanosheets and abun-dant pores, endow the Nb_(2)O_5 microflower with highly reversible Na ion storage capacity of 245 mAh g^(-1) at 0.25 C and excellent rate capability.Benefiting from high capacity and fast charging of Nb_(2)O_5 microflower, the planar NIMSCs consisted of Nb_(2)O_5 negative electrode and activated car-bon positive electrode deliver high areal energy density of 60.7 μWh cm^(-2),considerable voltage window of 3.5 V and extraordinary cyclability. Therefore, this work exploits a structural design strategy towards electrode materials for application in NIMSCs, holding great promise for flexible microelectronics.展开更多
Service life of two different oxide anodes in phenolsulfonic acid (PSA) solution was investigated by accelerated electrolysis. The durability of Ti/IrO_2+Ta_2 O_5 anode increased by the addition of SnO_2 in the mixed...Service life of two different oxide anodes in phenolsulfonic acid (PSA) solution was investigated by accelerated electrolysis. The durability of Ti/IrO_2+Ta_2 O_5 anode increased by the addition of SnO_2 in the mixed oxides. The degradation mechanisms of Ti/IrO_2+ Ta_2 O_5 and Ti/IrO_2 +Ta_2 O_5 +SnO+2 anodes were different. It was shown from the observation of scanning electron microscopy (SEM) and the electrochcmical measurement that, the deactivation of Ti/IrO_2 + Ta_2 O_5 anode was due to the build-up of an organic film on surface. The growth of the covered film on surface was restricted by addition of SnO_2, which resulted in increasing of the service life of anodes. The over-potential for oxygen evolution on Ti/IrO_2 +Ta_2 O_5 electrode increased after doping SnO_2, and the intermediate products of PSA building-up on the surface was much more rapidly oxidized. Meanwhile, a certain part of the surface oxide deposit entered into the solution leading to loss of oxides, which resulted in degradation of Ti/IroO_2 + Ta_2 O_5 anode containing SnO_2 component.展开更多
Wet scrubbing combined with ozone oxidation has become a promising technology for simultaneous removal of SO_2 and NO_x in exhaust gas.In this paper,a new 20-species,76-step detailed kinetic mechanism was proposed bet...Wet scrubbing combined with ozone oxidation has become a promising technology for simultaneous removal of SO_2 and NO_x in exhaust gas.In this paper,a new 20-species,76-step detailed kinetic mechanism was proposed between O_3 and NO_x.The concentration of N_2O_5 was measured using an in-situ IR spectrometer.The numerical evaluation results kept good pace with both the public experiment results and our experiment results.Key reaction parameters for the generation of NO_2 and N_2O_5 during the NO ozonation process were investigated by a numerical simulation method.The effect of temperature on producing NO_2 was found to be negligible.To produce NO_2,the optimal residence time was1.25 sec and the molar ratio of O_3/NO about 1.For the generation of N_2O_5,the residence time should be about 8 sec while the temperature of the exhaust gas should be strictly controlled and the molar ratio of O_3/NO about 1.75.This study provided detailed investigations on the reaction parameters of ozonation of NO_x by a numerical simulation method,and the results obtained should be helpful for the design and optimization of ozone oxidation combined with the wet flue gas desulfurization methods（WFGD） method for the removal of NO_x.展开更多
The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microsc...The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microscope) and XRD (X- ray Diffraction) techniques. Themechanical properties such as bending strength and fracture toughness, as well as their changes withadvancing crystallization were determined. The results show that the changes of the mechanicalproperties are correlated with the microstructures. The sample heated up to 810 deg C and soaked for4 h has smaller crystalline size and less volum fraction of fluorophlogopite, so it has higherbending strength (about 190 MPa), and higher crack toughness (about 2.63 MPa centre dot m^1/2).展开更多
The morphology, size and phase of the material play a crucial role in its electrochemical performance.Herein, the nano-sized niobium pentoxide(Nb2O5) with different morphologies and phase structures are synthesized th...The morphology, size and phase of the material play a crucial role in its electrochemical performance.Herein, the nano-sized niobium pentoxide(Nb2O5) with different morphologies and phase structures are synthesized through a very simple thermal treatment method, including the pseudo hexagonal Nb2O5nanosheets and pseudo hexagonal Nb2O5nanoparticles, orthorhombic Nb2O5nanoparticles. The synthesized pseudohexagonal Nb2O5 nanosheets and orthorhombic Nb2O5nanoparticles exhibit better cycling and rate performance than the pseudohexagonal Nb2 O5 nanoparticles due to the different morphologies and phase structures. The T-Nb2O5-700 nanoparticles show the higher capacity(175 mAh/g) than that of TT-Nb2O5-500 nanosheets(127 mAh/g) and TT-Nb2O5-600 nanoparticles(39 mAh/g) at a current density of 50 mA/g and good rate performance with a capacity of 140 mAh/g at 1.0 A/g. The excellent rate capability and cycling stability of orthorhombic T-Nb2O5may be ascribed to the dominant contribution of pseudocapacitive effect. This material has the great potential as a practical high-rate anode material for lithium-ion batteries.展开更多
A mild,efficient and eco-friendly process for the electrophilic nitration is described using N_2O_5 as a green nitrating agent in the presence of rare earth metal triflates[RE（OTf）_3]under mild conditions.
The relationship between bond valence and bond covalency in RMn2O5 (R = La, Pr, Nd.Sm, Eu) has been investigated by a semiempirical method. This method is the generalization of thedielectric description theory of Phil...The relationship between bond valence and bond covalency in RMn2O5 (R = La, Pr, Nd.Sm, Eu) has been investigated by a semiempirical method. This method is the generalization of thedielectric description theory of Phillips. Van Vechten, Levine and Tanaka scheme. The resultsindicate that larger valences usually result in higher bond covalencies, in good agreement with thepoint that the excess charge in the bonding region is the origin of formation of bond covalency.Other factors, such as oxidation state of elements, only make a small contribution to bondcovalency.展开更多
The phase diagram of the binary system MnO-Nb_2O_5 was studied by means of the differential thermal analysis(DTA),X-ray diffraction analysis and scanning electron microscopy(SEM).Thermodynamic da- ta of the new compou...The phase diagram of the binary system MnO-Nb_2O_5 was studied by means of the differential thermal analysis(DTA),X-ray diffraction analysis and scanning electron microscopy(SEM).Thermodynamic da- ta of the new compounds 4MnO·Nb_2O_5 and MnO·Nb_2O_5were found as follows: 4MnO·Nb_2O_5:t_m=1398±2℃ △H_m=129000(J/mol) △S_m=77(J/mol,K) △G_m^o=129000-77T(J/mol) MnO·Nb_2O_5:t_m=1499±2℃ △H_m=86940(J/mol) △S_m=49.6(J/mol,K) △G_m^o=86940-49.6T(J/mol) The eutectic parameters for the system are given below: t_(E1)=1383±3℃ N_(E1(MnO))=0.896 t_(E2)=1312±2℃ N_(E2(MoO))=0.713 t_(E3)=1400±4℃ N_(E3(MnO))=0.231展开更多
Equilibrium between liquid iron containing Nb with Nb_2O5-MnO-SiO_2 slag was investigated at 1828 K,the solid electrolyte oxygen concentration cell being used to measure the activity of oxygen in the metal bath.The ac...Equilibrium between liquid iron containing Nb with Nb_2O5-MnO-SiO_2 slag was investigated at 1828 K,the solid electrolyte oxygen concentration cell being used to measure the activity of oxygen in the metal bath.The activity of Nb_O_5 and MnO in the slag was evaluated, accompanied with an iso-activity diagram of a_(Nb_2O_5) and a_(MoO) in Nb_2O_5-MnO-SiO_2 slay.展开更多
基金financially supported by the National Natural Science Foundation of China (Grants. 22075279, 22279137, 22125903, 22109040)National Key R&D Program of China (Grant 2022YFA1504100)+2 种基金Dalian Innovation Support Plan for High Level Talents (2019RT09)Dalian National Labo- ratory For Clean Energy (DNL), CAS, DNL Cooperation Fund, CAS (DNL202016, DNL202019), DICP (DICP I2020032)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy (YLU-DNL Fund 2021002, YLU- DNL Fund 2021009)。
文摘Planar Na ion micro-supercapacitors(NIMSCs) that offer both high energy density and power density are deemed to a promising class of miniaturized power sources for wearable and portable microelectron-ics. Nevertheless, the development of NIMSCs are hugely impeded by the low capacity and sluggish Na ion kinetics in the negative electrode.Herein, we demonstrate a novel carbon-coated Nb_(2)O_5 microflower with a hierarchical structure composed of vertically intercrossed and porous nanosheets, boosting Na ion storage performance. The unique structural merits, including uniform carbon coating, ultrathin nanosheets and abun-dant pores, endow the Nb_(2)O_5 microflower with highly reversible Na ion storage capacity of 245 mAh g^(-1) at 0.25 C and excellent rate capability.Benefiting from high capacity and fast charging of Nb_(2)O_5 microflower, the planar NIMSCs consisted of Nb_(2)O_5 negative electrode and activated car-bon positive electrode deliver high areal energy density of 60.7 μWh cm^(-2),considerable voltage window of 3.5 V and extraordinary cyclability. Therefore, this work exploits a structural design strategy towards electrode materials for application in NIMSCs, holding great promise for flexible microelectronics.
文摘Service life of two different oxide anodes in phenolsulfonic acid (PSA) solution was investigated by accelerated electrolysis. The durability of Ti/IrO_2+Ta_2 O_5 anode increased by the addition of SnO_2 in the mixed oxides. The degradation mechanisms of Ti/IrO_2+ Ta_2 O_5 and Ti/IrO_2 +Ta_2 O_5 +SnO+2 anodes were different. It was shown from the observation of scanning electron microscopy (SEM) and the electrochcmical measurement that, the deactivation of Ti/IrO_2 + Ta_2 O_5 anode was due to the build-up of an organic film on surface. The growth of the covered film on surface was restricted by addition of SnO_2, which resulted in increasing of the service life of anodes. The over-potential for oxygen evolution on Ti/IrO_2 +Ta_2 O_5 electrode increased after doping SnO_2, and the intermediate products of PSA building-up on the surface was much more rapidly oxidized. Meanwhile, a certain part of the surface oxide deposit entered into the solution leading to loss of oxides, which resulted in degradation of Ti/IroO_2 + Ta_2 O_5 anode containing SnO_2 component.
基金financially supported by the National High Tech Research and Development Program(863)of China(No.2011AA060801)the Program for Zhejiang Leading Team of S&T Innovation(No.2013TD07)
文摘Wet scrubbing combined with ozone oxidation has become a promising technology for simultaneous removal of SO_2 and NO_x in exhaust gas.In this paper,a new 20-species,76-step detailed kinetic mechanism was proposed between O_3 and NO_x.The concentration of N_2O_5 was measured using an in-situ IR spectrometer.The numerical evaluation results kept good pace with both the public experiment results and our experiment results.Key reaction parameters for the generation of NO_2 and N_2O_5 during the NO ozonation process were investigated by a numerical simulation method.The effect of temperature on producing NO_2 was found to be negligible.To produce NO_2,the optimal residence time was1.25 sec and the molar ratio of O_3/NO about 1.For the generation of N_2O_5,the residence time should be about 8 sec while the temperature of the exhaust gas should be strictly controlled and the molar ratio of O_3/NO about 1.75.This study provided detailed investigations on the reaction parameters of ozonation of NO_x by a numerical simulation method,and the results obtained should be helpful for the design and optimization of ozone oxidation combined with the wet flue gas desulfurization methods（WFGD） method for the removal of NO_x.
文摘The microstructure of CaO-P_2O_5-SiO_2-MgO-F^- glass-ceramics duringcrystallization were investigated and the crystallized phases were identified with DTA (DifferentialThermal Analysis), SEM (Scanning Electron Microscope) and XRD (X- ray Diffraction) techniques. Themechanical properties such as bending strength and fracture toughness, as well as their changes withadvancing crystallization were determined. The results show that the changes of the mechanicalproperties are correlated with the microstructures. The sample heated up to 810 deg C and soaked for4 h has smaller crystalline size and less volum fraction of fluorophlogopite, so it has higherbending strength (about 190 MPa), and higher crack toughness (about 2.63 MPa centre dot m^1/2).
基金supported by the National Natural Science Foundation of China(No.51302079)the Natural Science Foundation of Hunan Province(No.2017JJ1008)
文摘The morphology, size and phase of the material play a crucial role in its electrochemical performance.Herein, the nano-sized niobium pentoxide(Nb2O5) with different morphologies and phase structures are synthesized through a very simple thermal treatment method, including the pseudo hexagonal Nb2O5nanosheets and pseudo hexagonal Nb2O5nanoparticles, orthorhombic Nb2O5nanoparticles. The synthesized pseudohexagonal Nb2O5 nanosheets and orthorhombic Nb2O5nanoparticles exhibit better cycling and rate performance than the pseudohexagonal Nb2 O5 nanoparticles due to the different morphologies and phase structures. The T-Nb2O5-700 nanoparticles show the higher capacity(175 mAh/g) than that of TT-Nb2O5-500 nanosheets(127 mAh/g) and TT-Nb2O5-600 nanoparticles(39 mAh/g) at a current density of 50 mA/g and good rate performance with a capacity of 140 mAh/g at 1.0 A/g. The excellent rate capability and cycling stability of orthorhombic T-Nb2O5may be ascribed to the dominant contribution of pseudocapacitive effect. This material has the great potential as a practical high-rate anode material for lithium-ion batteries.
基金the financial support from the National Nature Science Foundation of China Academy of Engineering Physics(No.10976014)Nature Science Foundation of Jiangsu Province(No.BK2011697)
文摘A mild,efficient and eco-friendly process for the electrophilic nitration is described using N_2O_5 as a green nitrating agent in the presence of rare earth metal triflates[RE（OTf）_3]under mild conditions.
文摘The relationship between bond valence and bond covalency in RMn2O5 (R = La, Pr, Nd.Sm, Eu) has been investigated by a semiempirical method. This method is the generalization of thedielectric description theory of Phillips. Van Vechten, Levine and Tanaka scheme. The resultsindicate that larger valences usually result in higher bond covalencies, in good agreement with thepoint that the excess charge in the bonding region is the origin of formation of bond covalency.Other factors, such as oxidation state of elements, only make a small contribution to bondcovalency.
文摘The phase diagram of the binary system MnO-Nb_2O_5 was studied by means of the differential thermal analysis(DTA),X-ray diffraction analysis and scanning electron microscopy(SEM).Thermodynamic da- ta of the new compounds 4MnO·Nb_2O_5 and MnO·Nb_2O_5were found as follows: 4MnO·Nb_2O_5:t_m=1398±2℃ △H_m=129000(J/mol) △S_m=77(J/mol,K) △G_m^o=129000-77T(J/mol) MnO·Nb_2O_5:t_m=1499±2℃ △H_m=86940(J/mol) △S_m=49.6(J/mol,K) △G_m^o=86940-49.6T(J/mol) The eutectic parameters for the system are given below: t_(E1)=1383±3℃ N_(E1(MnO))=0.896 t_(E2)=1312±2℃ N_(E2(MoO))=0.713 t_(E3)=1400±4℃ N_(E3(MnO))=0.231
文摘Equilibrium between liquid iron containing Nb with Nb_2O5-MnO-SiO_2 slag was investigated at 1828 K,the solid electrolyte oxygen concentration cell being used to measure the activity of oxygen in the metal bath.The activity of Nb_O_5 and MnO in the slag was evaluated, accompanied with an iso-activity diagram of a_(Nb_2O_5) and a_(MoO) in Nb_2O_5-MnO-SiO_2 slay.
