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
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
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
Aqueous Zn-N_(2)batteries with unique configuration are of potential for simultaneous N_(2)electro reduction and electricity generation,in which the electrocatalysts are critical for improving the NH_(3)yield and the ...Aqueous Zn-N_(2)batteries with unique configuration are of potential for simultaneous N_(2)electro reduction and electricity generation,in which the electrocatalysts are critical for improving the NH_(3)yield and the energy efficiency.Herein,a heterostructure Nb_(2)O_(5)/Nb_(2)CT_(x)with abundant exposed Nb active sites and tuned electron density has been synthesized by in situ formation and anchoring of Nb_(2)O_(5) nanoparticles on the surface of Nb_(2)CT_(x)MXene,which shows an enhanced N_(2)adsorption/activation capacity.The heterostructure Nb_(2)O_(5/)Nb_(2)CT_(x)was used as the cathode of Zn-N_(2)battery that can deliver a peak power density of 1.25 mW cm^(-2)in 1.0 M KOH and can continuously produce NH_(3)with a yield of3.62μg h^(-1)mg_(ca)^(t-1).The NH_(3)formed in the battery system can be easily collected as a net product without circulating the electrolyte.Moreover,the Nb_(2)O_(5/)Nb_(2)CT_(x)has a long durability,evidenced by 70 h of operation at-0.4 V vs.reversible hydrogen electrode,which is the highest among the MXene-based electrocatalysts reported thus far.This work may provide a new methodology based on Zn-N_(2)battery for sustainable and large-scale NH_(3)production with minimal energy consumption.展开更多
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.
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.
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
基金supported by the National Natural Science Foundation of China(Nos.U24B20198,22308139,52071171,52202248)the Natural Science Foundation of Liaoning Province(2023-MS-140)+8 种基金the Key Research Project of Department of Education of Liaoning Province(LJKZZ20220015)the Australian Research Council(ARC)through Future Fellowship(FT210100298)Discovery Project(DP220100603)Linkage Project(LP210200504,LP220100088,LP230200897)the Industrial Transformation Research Hub(IH240100009)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)the Australian Renewable Energy Agency(ARENA)as part of ARENA’s Transformative Research Accelerating Commercialisation Program(TM021)European Commission’s Australia-Spain Network for Innovation and Research Excellence(AuSpire)the Foundation of State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology(MJNYSKL202301)。
文摘Aqueous Zn-N_(2)batteries with unique configuration are of potential for simultaneous N_(2)electro reduction and electricity generation,in which the electrocatalysts are critical for improving the NH_(3)yield and the energy efficiency.Herein,a heterostructure Nb_(2)O_(5)/Nb_(2)CT_(x)with abundant exposed Nb active sites and tuned electron density has been synthesized by in situ formation and anchoring of Nb_(2)O_(5) nanoparticles on the surface of Nb_(2)CT_(x)MXene,which shows an enhanced N_(2)adsorption/activation capacity.The heterostructure Nb_(2)O_(5/)Nb_(2)CT_(x)was used as the cathode of Zn-N_(2)battery that can deliver a peak power density of 1.25 mW cm^(-2)in 1.0 M KOH and can continuously produce NH_(3)with a yield of3.62μg h^(-1)mg_(ca)^(t-1).The NH_(3)formed in the battery system can be easily collected as a net product without circulating the electrolyte.Moreover,the Nb_(2)O_(5/)Nb_(2)CT_(x)has a long durability,evidenced by 70 h of operation at-0.4 V vs.reversible hydrogen electrode,which is the highest among the MXene-based electrocatalysts reported thus far.This work may provide a new methodology based on Zn-N_(2)battery for sustainable and large-scale NH_(3)production with minimal energy consumption.
